The short answer, while it doesn't make mad, then, is to not buy any gunshow AK, FAL, M14 or any rifle potentially built by another guy, such as a Savage, VZ-58, either. It also means never to buy a used car, or a used drill, or for that matter anything that is not directly from the dealer, regardless of the product.
I disagree. The FAL isn't a CETME or HK-91. Problems with the build do not make the rifle DOA. If the components are fundamentally sound, such as a good receiver, a barrel that isn't shot-out, etc, then there is no big deal with them. I have never heard or read of FAL's being such a problem that you can never afford to buy them from anyone but a stocking dealer. That would fundamentally make their value on the secondary market very low. But, then, FAL's retain their value and have consistently risen in value, and that includes Century builds. And with Century builds, they are generally rock solid. The only problem with them has traditionally been the receiver. If it is not a Hesse or other uni-brow, if it is a Century built Imbel or Argentine, regardless of inch or metric, then they generally work great. I have done FAL's for 15 years now, and that is my experience.
I have never paid more than $800 for an FAL, and that was for an Israeli Heavy Barrel. Well, if you don't get one built by Springfield Armory, then you will never own one because Century never built any - they are all gunsmith builds. Heck, I even owned a Hesse-receiver Century R1a1 and it ran just fine.
Ash