Do people who live in extremely bad conditions, in very poor 3rd world
countries, where there is luck of food, lethal diseases, etc, attempt
to commit suicide, and if so, in what rate? I am not interested in
detailed numbers, but on an estimation, in proportion to the rate of
people who attempt or commit suicide in 1st world countries (are they
significantly more, significantly less, or about the same).

It appears that, although economic status is a factor in suicides, it
is not the overwhelming factor that one might expect it to be. The
ethnic, cultural, and religious influences that are present in various
nations seem to be as important as hardship factors and economic
circumstances. Rather surprisingly, both the nations with the highest
suicide rates and the nations with the lowest suicide rates tend to be
countries where economic hardship is common. The suicide rates of the
world's more affluent countries fall somewhere in the middle, and many
industrialized countries have higher rates of suicide than do poorer,
developing "Third World" countries.

According to World Health Organization data, these are the 10
countries with the highest suicide rates:

Country    Suicides per 100,000 inhabitants per year 
----------------------------------------------------
Russian Federation   86.6 
Lithuania            84.4
Estonia              78.4
Latvia               71.3 
Hungary              64.8
Slovenia             61.9
Kazakhstan           61.4
Sri Lanka            61.3
Belarus              58.3 
Finland              49.4

These are the 10 countries with the lowest suicide rates:

Country    Suicides per 100,000 inhabitants per year 
----------------------------------------------------
Guatemala             1.0 
Peru                  1.0
Jamaica               0.7 
Iran                  0.4
Syrian Arab Republic  0.2  
Egypt                 0.1 
Antigua and Barbuda   0.0  
Dominican Republic    0.0  
Honduras              0.0  
Jordan                0.0  

From the data above, we see that the nations with the highest rates of
suicide are the Baltic states.

More on the suicide rates of the Baltic states:

Radio Free Europe/Radio Liberty
http://www.rferl.org/nca/features/2002/04/09042002073543.asp

Here is a chart from the World Health Organization that shows male and
female suicide rates by country:

Commission on Macroeconomics and Health (see page 14)
http://www.cmhealth.org/docs/wg1_paper12.pdf

Here you'll find a bar chart showing male and female suicide rates of
different nations:

Universität Würzburg: International Academy for Suicide Research
http://www.uni-wuerzburg.de/IASR/suicide-figure1.htm

This chart gives numerical data on male and female suicide rates
worldwide:

Fathers for Life
http://www.fathersforlife.org/health/who_suicide_rates.htm

Other useful sources:

World Health Organization
http://www.who.int/violence_injury_prevention/media/en/483.pdf

Universität Würzburg: International Academy for Suicide Research
http://www.uni-wuerzburg.de/IASR/suicide-rates.htm
http://www.uni-wuerzburg.de/IASR/suicide-table1.htm

Suicide Lodge
http://www.a1b2c3.com/suilodge/facenc1.htm

Yahoo News
http://in.news.yahoo.com/030525/139/24l5d.html

Religious Tolerance
http://www.religioustolerance.org/sui_fact.htm

Intermountain Regional EMS for Children Coordinating Council
http://www.irecc.org/sor_tbl2.htm

Regarding the reliability of such data:

"Several analyses have aimed to assess the comparability of
international suicide mortality data. Studies in the United Kingdom
have clearly shown the influence of recording procedures. For example,
the lower suicide rates in Scotland, compared with England, were
explained by a higher proportion of undetermined intent cases in
Scotland (fewer autopsies and a more restrictive definition of
suicide). Inversely, similar studies comparing Nordic countries
concluded that the lower rates observed in Norway were not due to
differences in practices between countries. Our results about
international ranking are in the same vein as those of earlier
studies: the overall hierarchy of suicide rates by country appears to
be real even after the potential reporting bias is taken into account.
The general conclusion of these investigations is that the differences
in certification and recording practices are not sufficient to explain
the great variation in suicide rates between countries. Another
interesting approach compared the suicide rates of immigrants in one
country to those observed in their country of origin. These studies
highlight a strong correlation between the two types of classification
and conclude that the deviations in suicide rates reported between
different countries are reliable.

Australian Institute of Health and Welfare
http://www.aihw.gov.au/international/who_hoc/hoc_02_papers/brisbane29.pdf

Google search strategy:

Google Web Search: "suicide rates by country"
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=%22suicide+rates+by+country

Thank you for an interesting (if grim) project. I hope this
information meets your needs. If anything is unclear, or if a link
does not function, please request clarification; I'll be glad to offer
further assistance before you rate my answer.

Best regards,
pinkfreud