Are you questioning the cost ($50 per wheel) Thats cheap for what your doing honestly the only thing i would question is the way they balance the wheels . I work at a tire shop the going rate for a standard 20 (20x8-20x9 w/35 and up series tires ) is about $50 . You also talking about a strech now some shops shy away from that for legal reasons If something was to happen and you had a blow out it would be the shops fault . So when they tell you 50 take that if they can do it . Just my .02