A lot of upholstery work is what you don’t see. A seat may look well done until a seam fails or an insert lets go, then it is apparent all upholsters are not equal. I see a lot of interiors where pleats don’t line up and wavy seams. As said, it is the little stuff that makes the difference. A nice interior and good work seldom come cheap. In the case of the o/p it may hard to justify an spendy interior depending on the car’s potential value.