Is it legal for an Iraninan American (one that has dual citzenship of
Iranian and American citizenship) to transfer a sum of $150k to $500k
from Iran to the U.S.?    I stand to inherit real estate in Iran worth
some $150k to $500k and I wanted to know if the Iranian government
would let me bring that money out of the country to the U.S. or would
they force me to keep it in Iran?  I say this because I would be
selling Iranian real estate (that I would inherit) and taking that
money and bringing it with me to the U.S.

Such a transfer does not appear to be affected by US sanctions, but
permission to transfer such a large amount from Iran would appear to
require the permission of the Iranian Central Bank for it to be legal.
 They may very well object, so I would seek to obtain all necessary
permissions before I bothered to try.  The amount you can transfer in
US$ is very limited without permission, as is the amount of Iranian
currency you could transfer (various sources conflict on the precise
amounts).  And, I expect you would have trouble converting the Iranian
currency in the US if you did somehow manage to get it here.  I have
provided the US contact for the Iranian government, along with
warnings and procedural information for dual-citizens planning to
travel to Iran.

I would also want to contact the Office of Foreign Assets Control of
the US Treasury to 1)ensure such a transaction would not violate any
US laws and 2)to find out how to properly report such a transaction to
US authorities.  Particularly if you anticipate carrying that amount
in cash on your person, there are procedures you must follow to
declare currency of more than $10,000 to US Customs.

Sincerely,

Wonko

Sources:

"Foreign Exchange

According to laws of central bank of the Islamic Republic of Iran, the
maximum permitted transferable foreign Currency by each passenger is
1000 dollars (Bank-note, traveler check or a combination of both).
Transfer of foreign Currency more than the allowed limit requires a
bank statement or a transfer certificate issued by the bank system.
Transfer of Dinar (Iraq), Ruble (Russia), and Afghani ( Afghanistan)
is prohibited by passengers and traders. Transfer of Iranian Currency
is allowed up to 500000 Rials."

"Customs in Iran" ISTA (2002) http://www.irantour.org/Iran/Customs.html

"Foreign exchange control 
The exchange market is regulated and controlled by the Government.
Only currencies brought from abroad can be repatriated afterwards.
Passengers are authorized to take out a maximum of USD 1,000 or the
equivalent in other currencies. The authority in charge of the
currency regulation is the Central Bank of Iran (Markazi bank).
Repatriation of profits, capital by a foreign investor is possible
with a three months' notice. In case of capital repatriation, the
foreign investor must keep 10% of his capital during six months as a
deposit for possible commitments. Applicable exchange rate is the
official ruling rate. Moreover, foreign currency transfers are not
carried out without delay, the latter can last up to six months or
more."

"Iran - Doing Business" FITA (December 2003)
http://www.fita.org/countries/iran.html?ma_rubrique=investissement

"Foreign Exchange
Imports are traded at US $1 = Rials 8,000. Exchange control authority
is vested in the Central Bank (Bank Markazi). All foreign exchange
transactions must take place through the Central Bank or authorized
banks. However, there is a black market in currency in Iran. As of
February 1 998, the black market rate for US$l was rials 4800. The
black market is illegal and subject to occasional crackdowns."

"Tehran office and doing business in Iran" CWC International (2004)
http://www.cwcgulf.com/iranoffice.htm

"Currency restrictions: There are no restrictions on the import of
foreign currency if declared on arrival. Export of foreign currency is
allowed up to the declared limit of imported goods. Import of local
currency is allowed up to RL 20,000 and its exports up to RL 200,000.
Any amount larger than that requires authorization from the Central
Bank."

"Iran" MuslimTrade Network
http://www.muslimtrade.net/tradeguideline/iran/index.html#_Toc413602358

"Exchange control authority is vested in Bank Markazi Jomhouri Islami
Iran (Central bank of Islamic Republic of Iran). All foreign exchange
transactions must take place through the banking system."

"Key Features of the Iran Exchange System" FarsiNet (2006)
http://www.farsinet.com/toman/exchange.html

"Overview of Sanctions" Office of Foreign Asset Control, US Department
of Treasury (March 12, 2003)
http://www.treas.gov/offices/enforcement/ofac/programs/iran/iran.pdf

"Money
There is no limit on the total amount of monetary instruments that may
be brought into or taken out of the U.S. However, if you transport
more than $10,000 in monetary instruments on any occasion into or out
of the U.S., a report must be filed with U.S. Customs. The form FinCEN
105 (Report of International Transportation of Currency or Monetary
Instruments) may be obtained when entering or leaving the US from a
customs official, or it can be downloaded here. Failure to declare
currency in amounts over $10,000 may be subject to forfeiture and
could result in civil and criminal penalties."

"Information on U.S. Customs" United States Embassy Stockholm
(February 7, 2006) http://stockholm.usembassy.gov/consulate/acs4.html

"ENTRY/EXIT REQUIREMENTS:  Should you decide to travel to Iran despite
the current Travel Warning, a passport and visa are required.  The
Iranian Interests Section of the Embassy of Pakistan is located at
2209 Wisconsin Ave. N.W, Washington, DC. 20007; tel 202-965-4990, 91,
92, 93, 94, 99, fax 202-965-1073, 202-965-4990 (Automated
Fax-On-Demand after office hours).  Their Internet Website is
http://www.daftar.org (click on ?View in English").  Possession of a
valid Iranian visa will not guarantee entry into the country as a few
American travelers have been refused entry at the border without
explanation.  U.S. passports are valid for travel to Iran.  However,
U.S.-Iranian dual nationals have in the past been denied permission to
enter/depart Iran documented as U.S. citizens and have had their U.S.
passports confiscated upon arrival, unless they have renounced their
Iranian citizenship.  Nevertheless, in recent years the Iranian
Government has become more lenient with dual nationals and rarely
confiscates U.S. passports of U.S. ? Iranian dual nationals.  As a
precaution, however, it is advisable for U.S.-Iranian dual nationals
to obtain in their Iranian passports the necessary visas for the
country which they will transit upon their return to the U.S., so that
if their U.S. passports are confiscated, they may apply for a new U.S.
passport in that country.

Alternately, dual nationals whose U.S. passports are confiscated may
obtain a ?Confirmation of Nationality? from the U.S. Interests Section
of the Embassy of Switzerland, which is the U.S. protecting power. 
This statement, addressed to the relevant foreign embassies in Tehran,
enables the travelers to apply for third-country visas in Tehran. 
Dual nationals finding themselves in this situation should note in
advance that the Swiss Embassy would issue this statement only after
the traveler's U.S. nationality is confirmed and after some processing
delay.  Dual nationals must enter and depart the United States on U.S.
passports."

"Iran" U.S. Department of State (February 8, 2006)
http://travel.state.gov/travel/cis_pa_tw/cis/cis_1142.html

Search terms:  Iran foreign exchange control; Iran exchange control;
Iran currency export; declaring currency US customs; iran consulate US

Keep in mind it that while it may be difficult to export currency from
Iran it may be easier to take goods out of the country for resale. It
may be hard to buy, export and resell $150-$500k worth of crude oil,
but there may be other world class items that are easier to export
such as high-end Persian rugs. It may mean that you will have to study
up on rugs and become an expert, perhaps even employ an expert to help
you purchase so as to not get ripped off. But, this is much more
preferable to leaving the money in a bank and waiting for a more
favorable political climate. Who knows, you may even be able to make
money in the process? Perhaps there are other world class Iranian
products easily available to resell outside of the country? Gold or
jewelery?

Emigrants have been dealing with and overcoming these problems for
centuries, you can find a way, too.

This suggestion is directed from a business perspective, not a
political or legal one.

Rugs is not such a wild idea.  Perhaps you could arrange with a US rug
dealer (or importer of other goods) to use your funds for purchasing
rugs and get reimbursed in US dollars, for a fee, no doubt.  However,
there MAY be export controls that define that funds for the purchase
must be transferred from abroad, which would upset this.
I would not be surprised if there are quite a few Iranians in the
States with your problem.  Maybe the community has some suggestions. 
Who knows, maybe the CIA would like to have some funds in Iran.  (My
apologies, if you find this facetious suggestion offensive.)

It also has occurred to me that maybe it is possible for you to
establish a bank-related credit card account in Iran from which you
could make cash withdrawals in the States.

I would say yes.  Although, I am not a lawyer.  There was a law just
passed that puts restrictions on countries that are label as terrorist
contries.  AON, just pulled out a hefty amount out of that country in
the last 2 months.  If you want more info on the law and its changes
let me know.