I've heard of offers as low as $48K for assistant professors in biological sciences. That's at a real PhD-granting research university, though admittedly not a particularly good one. Even lower for fields like English and History. Higher for hard sciences, and even higher for CS.
By the way, even your salary number seems low. Perhaps your numbers include teaching colleges?
As for summers, they are also a good time to build a startup. Most tenure review committees don't mind that sort of thing.