You might want to research the FNAR a little bit more. It lists for $1500 or so but lately many dealers have been selling them for a little under $1000. It's made by FN Herstal, one of the best firearms makers on the planet, and in order to get 1 MOA performance you basically just need to take it out of the box, install a scope, and start shooting. No tuning, no glass bedding, nothing.
As for .308 ARs, there is such a huge range that I wouldn't make any generalities. Some can probably shoot 0.5 MOA, others may be lucky to do 2 MOA. The DPMS .308s with free floating barrels tend to be very accurate, at the expense of being heavy and sometimes unreliable (my LR-308B has always been accurate but I'm still dealing with reliability issues). For the combination of accuracy, reliability, and durability, you might look at the KAC SR-25, LMT MWS, and Noveske, all of which will set you back more than $2k to start.
Really, unless discussing an exact model made by one specific company, it's hard to really compare accuracy with specific claims. Some FALs do 4 MOA, while some of DSA's SA58 models can realistically do 1-1.5 MOA. One guy's G3-derivative may shoot 1 MOA while another's may struggle to do 4 MOA. Etc. etc.