I'm going through the process to build my first FAL as well. For price, here's a breakdown of what I'm spending so far:
* New Imbel metric receiver (
AIM): $210
* FFL transfer of receiver: $20
* Used G1 metric kit (
Tapco): $100
* Handpick fee (Tapco): $20 (to get a good bore)
* New US made metric charger (Tapco): $15 (part of the 10 mag combo)
* New US made G1 muzzle break (Tapco): $20
* New US parts kit [trigger group,pistol grip,mag parts] (
RPB): $60
* New US metric gas piston (RPB): $30
So far, I'm into it for $460 plus shipping. I plan on putting most of it together myself, but I plan to have the hard stuff (barrel mounting/headspacing) done by a local gunsmith. After I've shot it and am happy, I'll probably have it reparkerized to match the receiver.
Because you want a carbine barrel, you might want to check out
DSA's site. A little pricey, but just about anything you want. If you have a smith handy, you could perhaps have the barrel from a kit cut down to carbine length.
Like Jonnie says, check out FAL Files for more information than you ever wanted to know.
LL