AK gunsmithing prices

I have a AK74m parts kit I need to have built. It should be everything I need to make a complete rifle. That would be a receiver, the barrel, gas blocks, rivets and pins. I have contacted the following companies:

Blackburn AK: $550 Appalachian Gunwerks: $575 M13: $575

With all of that being said, who would you pick from this list? Would you go with another company?