Randy,
some parts on these cars are pretty high, front grille assembly for example. However, a lot of parts are available aftermarket, usually (tho' not always) at better prices than you'll get from MB. And many of those parts are original, too. Anyway, it pays to shop around, but cosmetic parts in particular are not cheap.
Regarding fender replacement, besides the cost of the part, removal and reinstalling is not cheap. Notice that there are no bolts, the entire assembly is welded, making for a much more difficult and time-consuming repair. If your guy is good, he may be able to do a good repair for less than it would cost to replace the fender. It's something to consider.
George Davis
'69 280 SL Euro manual