Wow! $550 for a complete tailgate with all the electrical and door poppers and what not? that's a great price if so, but i think not, I priced them around here ,and they were near $800 and that was an empty shell,I got lucky and Carl had acsess to a few used ones,after looking inside and seeing how many different latches ,linkages ,and electrical components there is, I'd hate to have to swap the inner parts,good luck!
WSA, your email link in blocked, so all I can do is say call 843-838-3613 (Wilson's Auto)talk to Bernard(owner). It is a small local salvage yard and I know he has a Roadmaster tailgate that is in good shape.