You want a metric FAL because the parts are more common and very low cost.
Here's how you get an FAL at the most rock bottom cost possible -
buy an FAL G1 kit from TAPCO that includes either 6 compliant parts ($170) or 8 compliant parts ($200), add an Imbel reciever from Federal Arms Company
gunsnstuff.net ($189), and put a rifle together yourself (with help from the folks at
www.falfiles.com .
That's $359 + transfer fee for the receiver, and taxes for a functional and legal FAL, but not including the tools you will need to fabricate to assemble the rifle. See the gunsmithing forum at
www.falfiles.com Magazines are $5 to $8 each for metric FAL's!
You might be able to do the job cheaper by buying a $100 parts kit from TAPCO and scrounging parts even cheaper than they are putting in the kits, but it would take research and patience.