Well in my opinion the peak of the Ed's career's long past, but I still respect him greatly for putting out such great music decades ago. The 5150 III is a great amp in it's own right though, so I wouldn't really call it some lame ass marketing ploy, since the actual product is good. But yeah you can only imagine that it wouldn't cost as much is Ed's name wasn't on it.
edit: then again, on second thought, if it weren't for Ed's collaboration with Fender, the 5150 III would never have seen the light of day.