I remember looking at them last year, S&W M&P's were going for under $ 500 all over. I'm kicking myself for not buying one then. The price of every kind of gun went up at least 40%, the prices of AK's went up even more, all in less than a year.
A quick search of gundeals reveals this unknown name to me flat top AR for $ 500:
https://www.sportsmans.com/shooting-...gn=Custom+Link
I've never done business with the selling company, so I'm not making an endorsement or recommendation.