I don't. They know they'll get their R&D costs back on the body in just a few figures. With a super hero line, a male muscle body will get plenty of use
The GI Joe line's prices fluctuate with the complication of the figure and the amount of accessories he comes with. The new Snake Eyes was $200, b
ut the next figure after him, Major Bludd was only $175. Just because they hit a new price bracket doesn't mean they'll all be that price. Batman will likely be more expensive than Superman because he has lots of toys he can come with.
Superman will be light on accessories unless they include things like kryptonite and broken pieces of buildings or something. I doubt they'd go the full Clark to Supes route, but that would be one way to flesh him out.
Joker comes with a lot of goodies, 2 heads, and 2 different looks (albeit its just a trenchcoat to go with the second, hatted head). I don't expect every character to be as equipped as him, like Superman. So I wouldn't panic about prices just yet until we see another figure in the line.