E.F.
If you borrow a crib, you need to really check it for safety... not just the "coke can" test, but for corner posts (they must be either no higher than 1/16th of an inch or at least 18 inches high, test the strength of the slats, the support mechanisims, etc. There is a lot of debate on whether to use a second-hand crib, but this is how I look at it: the crib is the only place in the house where you can reasonably expect to put your baby unsupervised. Shouldn't his or her safety there be the most important thing? Is it worth the couple hundred bucks you might have saved if (God forbid) anything goes wrong? Just my 2 cents...
If money is really a concern, a Pack and Play may be safer than a used crib. If you just don't want to get ripped off, I would check out the chapter in cribs in the Baby Bargains book by Denise Field... good discussion of what's available.
Good luck, and congratulations!