People have become used to paying about $50/game, if you want a console game, it's usually $50, if you want a PC game, $50, unless you're buying some old software, or something produced by a cheap company, like those guys who make the deer hunter clones. If a serious publisher started putting out games for $20 put in nothing but the jewel case people would dismiss it as lower-quality.
I do miss the good manuals and fun stuff they used to put in the boxes, now it seems like it's a burden for them to actually print out installation instructions.

Judging by the way they've been cutting out the extras I figure it won't be too long before we're paying $50 for the jewelcase.