you should try to list it at greatdomains.com
I'm pretty sure they'd accept it, but it might not be worth it.
Here are some recent keyword.cc sales (source:
http://www.namebio.com)
Rankings.cc $500 2006-12-04 Afternic
billiards.cc $400 2006-11-28 Afternic
billiards.cc $400 2006-11-28 Afternic
admission.cc $99 2006-11-01 Afternic
wrap.cc $75 2006-10-30 Afternic
Attorney.cc $1,000 2006-10-30 Afternic
Snooker.cc $650 2006-10-24 Afternic
videogame.cc $160 2006-10-17 Afternic
want.cc $150 2006-10-17 Afternic
Lawyer.cc $500 2006-10-16 Afternic
organizer.cc $75 2006-10-11 Afternic
Stats.cc $105 2006-10-09 Afternic
prototype.cc $75 2006-10-09 Afternic
tofu.cc $100 2006-10-09 Afternic
flags.cc $99 2006-10-09 Afternic
wind.cc $90 2006-10-04 Afternic
actors.cc $75 2006-09-28 Afternic
drinks.cc $75 2006-09-28 Afternic
sticker.cc $80 2006-09-21 Afternic
The general trend here seems to be that of increasing value. However, notice that these are all nouns, and what you've got here is an adjective. The nice thing about that is that is can be used for more things. Unfortunately, that's also a bad thing, since ccTLD's like this are usually only high sellers when the keyword is a targeted niche with high popularity.
Let's take a look at the overture scores for your keyword and a few of these sales:
1907 expensive
==============
1011971 lawyer
681063 video game
18314 ranking
So as you can see, how popular the keyword is has a strong effect in the value of .cc's (as it does with other extensions, however, MyBestFriends.com is more likely to have value than MyBestFriends.cc)
So I'd say expensive.cc has a value of around mid xx right now, especially since expensive kind of has a negative connotation. If you can turn the name into a positive one by, say, starting a blog with articles about expensive things that all of us middle class people want, then I think you'd get some more out of your money.
Hope this helps,
Jorge