Mark goes by FWRA on falfiles.com, and has ads in the marketplace forum. To files members (how hard is it to join another board) the 90% kits are $545, and other kit grades and pics are posted. He has a little shop just N of Akron, a flawless rep for dealing on falfiles, and I drop in sometimes just for show and tell. And he handled my FAL transfers for just $10!!
With all the FALs being built, a pre-ban receiver under $300 would be a shock to me. I built my basic Imbel from a Dan's kit (falparts.com) that was imported before the ban. I even printed off the statement from the web site and put it in the deposit box with my other gun receipts, just in case.
If you can find a fixed, US part buttstock, I doubt anyone will ever question your build but get the parts count right anyway.