Having them scratch built at a shop can be dicey unless you know the quality of the shop. An old mom and pop shop may only charge $50 an hour + materials but even then, a $500 cover with the correct color and grain is pretty reasonable. My buddy does high end custom upholstery. Like scratch built interiors for show cars. He charges $100/hour and he is a Legendary dealer. He says he can't do them himself for the price you pay.