i think £100 sounds reasonable. The body shop i use is DS Autobodies in Debtford in Sunderland. One man band called Daryl Sanders. i have used him for years and been brilliant! i just recently got a front end respray on my GTI and it cost me £450. That was wings, bumper, bonnet, mirrors, roof polish due to scratch at rear, put a stone guard coating on my front arch inners to make them more durable and blended half of front doors and a-pillars and looks absolutely perfect!
My whole family uses him when needed i wouldn't go anywhere else!
Thom