Cost for dual exhaust?

I'm ready to put on pipes and went to a local shop... he quoted me $800 out the door to put on the pipes and mufflers. It sounds quite high to me.

My car is a 73 Duster 318 with 340 exhaust manifolds. I have the old flanges and some hardware. I was thinking 2.5" pipes and Dynomax mufflers, although I don't have much to compare with.

Does anyone have an idea of a ballpark figure for pipes and installation?

Thanks!
Trevor