I just went through this last year.
924Board.org :: View topic - My interior redo (pic heavy)
The lowest price for custom cloth/vinyl seats from a local guy was 900 bucks , highest was almost double. (front and back seats) Thats for vinyl/cloth and he would have to make them from scratch. Stripping and recovering them is relatively easy, even I could do it. It's pretty straightforward and I took lots of pics just in case.