I do not know if you guys are aware that SMS purchased the equipment to make the comfort weave years ago. So what they are selling if probably repo material that they made. Yes it is expensive but also expensive to set up and make small batches.
I have 3 of the super rare Towne Top removable hard tops for 1964 1/2 - 1968 mustang. They never made but a few to start with they cost too much at $289. I have a copy of the production sheet from the factory and just a couple pages. I sent samples to SMS and they had both the exterior vinyl covering and the headliner material in stock. They have not made these since 1966.
We had a local trim shop here that had many of the original materials and it burnt down. I had my 1950 Ford redone with all original Factory material in 1966 for $148. That was everything in the car, headliner, seats, door panels, rear panels cardboard's for package tray and kick panels along with carpet. I dropped off at 8:00 in the morning and drove it home 3:00 that afternoon. Looked and smelled like a new car. My pay then was $1.00 an hour before taxes. So that was nearly 5 weeks pay back then. So the price that SMS is giving is pretty cheap I think in today's money. Would you give 4 or 5 weeks pay for an interior, NOT. I paid the local Ford dealer to paint the car $100 for exterior and the dash and metal frames around the windows inside. Did all this before I got out of high school. I was only car nut at school.
I bought an original Ginger comfort weave seat covers off ebay in great shape for $135.00 front and rear. I also think the new repo seat covers are the woven material not the stamped like the old repo was.
When I bought my Mach 1 I actually checked the price for buying from Ford a new set of seat covers to put up. I think they were like $400 each from Ford when new. Crazy expensive so I did not do it.
I have my own upholstery sewing machine and went to the Tech College and took a course in upholstery. It is the most difficult part of restoring a car to me. A person like the instructor could blow through an entire interior for a P.U. in one 4 hour class. Take it out, cut new, sew it up and install and back in the vehicle. Like everything practice makes perfect. An upholstery machine can sew 11 inches a second and go through a half inch of material, so a finger is nothing, ouch.