Unless your state has a specific law against only the receiver has to have an ffl, I have bought a couple that came straight from and unlicensed individual to my ffl dealer who in turn "yellow sheeted" them to me..I have sold 1 firearm to a fella in another state. I shipped it direct to a federally licensed dealer who in turn processed it to the buyer.:shrug:Do they want a good shotgun cheap? Or a cheap shotgun?
https://www.gunsamerica.com/Default.aspx
But remember if you buy on-line and have it shipped to you, you will need someone with a FFL license, both sending and receiving. (and they normally charge)
So with the charges and shipping, unless you want a specific firearm, your best bet is the local paper, pawn shops, gun shows, dealers and don't forget friends that are short of money.