When the seat price goes over $100 you may check with a small local re-upholsterer.  May get it done for less.  When I I I did my airplane seats a few years ago, the aircraft re-upholsterer want over $400 for just the two front seats.  Since airplanes require fire resistant fabrics I bought the fabrics from aircraft supplier for $30 and a local auto seat guy cut new foam and re-upholstered the fabric into a nice tuck and roll seat for $75 a seat.  I had to check the weight, but no change from the original. It never hurts to look.