I agree, the labor cost of tint is(should be) universal..ur house, car, boat, etc. should all be similar in cost if the same amount of film is used. UNLESS u have some kind of design u want in the tint OR u have a pain-in-the-*** car that requires more work...i.e crazy rear window design OR old tint film that needs removal. You probably ran into a greedy punk thats got his eye on a new aluminum wing for his Civic. However, one problem I have noticed in Benz, especially 210 chassis, is the inside window seals on the doors (at the top of the door panel, inside) over time scratchs the tint film badly...this looks crappy and is difficult to see out of. The more u use ur power windows the more they get scratched. IS IT possible he gave you an estimate to R&R the inside door panels and remove, and/or modify these seal strips in some way that they will not damage the film? If so....it is worth it..

If not...then find someone else....cost should be around 125-200 bucks...or so.