A face-to-face sale is entirely legal in most states, or any state I'd ever want to live in. The buyer and seller have to reside in the same state as the transaction. If you don't know the other party, I'd ask them to bring a photocopy of their state driver's license. Barring that, if they have a concealed handgun license, ask to see it. Keep emails etc about the transaction. Print them and file them.
But your later post about waiting is correct. the current feeding frenzy is the result of the ignorant suddenly waking up and realizing "everyone in the US has an AR except me, and Obama is about to cut me off". ARs and Aks will be available for some time to come. Neither is worth the prices some vendors are chargin lately.
Best bet right now is to buy a stripped lower receiver. It's the only regulated part. these are going for over $125 most places, but there are deals. There is a group buy going on 1919M4.com for $78 + shipping.