Mechanics yes, had an ecu get water damaged, that was steep. Modern Mercs always suffer with electrics. Bodywork though is the same surely, depending on who you know? Has been in my experience, once got a bmw bumper sprayed for 75 notes - can't imagine that even the mobile touch up vans would be cheaper than that
Any private job (i.e. not insurance claim) we did in my old bodyshop was always ridiculously priced. For a simple Bumper respray we'd have charged anywhere between £150-£200.
Mercedes bodywork mostly comprises of Aluminium panels these days, which is more expensive than steel, and more of a pig to work on.