How much is Kilmarnock.com worth?

that depends how much you prepared to pay for it and how much the
owner is prepared to sell it for.
The value of a domain name depends where you buy it from. a .com
domain can be purchased for under $10. So this is officially how much
it is worth.

Domain name values are subjective.  Many factors can be considred when
valuating a name.

Availability of similar names: This name is the .COM version of the
term, with no added prefixes or suffixes.  Would be considered the
best possible name for someone looking for a Kilmarnock related domain
name.

Google results: Used as a measure of how often the term is used. 
'Kilmarnock' appears on 1,570,000 webpages within Google.  This is a
very respectable number of result pages indicating wide use of the
term.

Overture bids: Used as an indication of commercial demand in a term by
advertisers.  I see 10 paying bidders bidding on this term up to $.35.
 This tells me there is limited demand, with a few select companies
willing to spend money to advertise for this term.  These advertisers
may be considered potential buyers of the domain.

Overture suggestion tool: Used to indicate how often a term is
searched for in a month.  (Used
http://inventory.overture.com/d/searchinventory/suggestion/ )  Results
show 763 searched in October 2005.  This would be considered a low
number.

I would estimate a fair "end user" price for this name would be in the
$2000+ price range in a situation where neither the domain seller or
buyer were under pressure.  In a "quick sale" situation, or selling to
a domain reseller, a fair price would be ~$400

These are rough valuation methods used by domain name professionals at
NamePros (www.namepros.com) and other domain industry sites.  If you
needed further valuations you could sign up there and request free
appraisals from other members.

You can list your name for sell at http://www.nameslot.com it is A
privately owned forum where you can buy, sell & talk about domain
names. Free registrations, bonus tools and domain showcase.