I asked a Custom upholstery shop "how much?" They said Whooow, You DON"T WANT TO KNOW....
So, I did it myself on my REGULAR sewing machine , I bought heavy needles and upholstery thread and a yard of Red and another of white
Cost was under 20 bucks....Well, the foam was 15 bucks...2" everywhere and 3" under my seat...

