I don't think people complain about Ghostbusters prices because A) there really hasn't ever been anything proper from Ghostbusters the movies out there, especially of the guys and not the ghosts, and B) those figures seem a better return for you money.
With TDK, there's Hot Toys figures and a whole assortment of items from it to buy, there's no acceptance because it's not like there isn't alternatives. With TDK, it's like ok, why spend $30 each on 7" figures when for the price of a few of those I can have a much better DX Batman.
However, if Mattel did Batman 1989 in the MM line, those, like Ghostbusters, would probably get much less issues with the pricing because again, there's never been official, accurrate product from that film of the characters, people would happily pay $30 for a figure they've dreamed someone would do for 20 years.
Hopefully Mattel would be smart enough to realize this and not base future products on the success or fail of the remainder of the TDK offering. I think, if they have the license, they should do Batman only from the 1989 film, just as a test, sell him, and see how it's received and I think they'd see results that favored doing Joker, maybe even Bob the Goon and expanding into Returns. You may not get enough folks spending $30 on figures from Forever and B&R, but surely the Burton film figures could sell.