OK...I know how much it sucks to be broke, and I realize that some guys have gotten lucky with the CAI FALs, but the other side of that coin is that when money is hard to come by, the last thing you need to do is to spend precious resources on a dice-roll, which is what the CAI guns basically are. What happens if the CAI gun you bring home turns out to be a giant turd?
If you can get a knowledgable FAL guy to go with you to a show, etc. where there are several of these guns, you may very possibly find one worth the money, and more power to you for getting a decent rifle at a good price. My suggestion would be to haunt the EE boards here and over at FALFiles. This is actually a good time of year to buy, and you may well find a better rifle built-up by someone knowledgable for your $400-500 cash.
Another possibility is the build-it-yourself-with-a-little-help route. Dan's Sporting Goods...http://www.falparts.com/...is honest and reputable and sells grade III kits for $129 that are excellent. FAC sells non-gear Imbel receivers for $189, and Tapco sells U.S. parts cheap. Put out a call for FAL builders in your general area...I'll bet there are several...and buddy-up to build your own rifle. In the process, you'll learn the rifle forwards and backwards, make some friends, and end up with a much better rifle IMO. True, this won't solve the "I wanna shoot it NOW" syndrone, but it is one answer to your problem.
Good Luck whatever you do, and HiramRanger is right-on about the CETMEs.