I second doing your research before purchasing. The major item to look for (especially from unscrupulous sellers) is whether the parts you're looking to buy are metric or inch. There's a LOT of BS out there from dealers and others who don't know anything about these except that they're black rifles. I routinely see Century rifles that haven't had the required US parts replacements put in, yet they have the thumbhole stock removed and are trying to sell them as pre-ban.
The market for FALs is indeed growing. Several manufacturers are bringing out new receivers this year. As Destructo said, of the current mfgr's the Imbel is great and so is the DSA (if you can find one).
You will see quite a disparity in pricing on FALs. That's because there are quite a few Belgian FALs in the USA. These have minor differences from all of the clones and command a premium over all others. You can see some of the rarer variations of these going over $4000. The clones or kit rifles go for around $600 - $800. Or you could build a kit yourself though you probably won't save too much over buying a clone, though you'll have the satisfaction of building it yourself. Building one yourself is relatively easy, the only difficult part that you may want a 'smith to do is headspacing. That's because the FAL headspaces on the locking shoulder. Different LS will give different sizing requirements.
Good luck on whatever you decide.