$50 doesn't sound unreasonable, $80 is probably pushing it, but then if you want something you'll pay more for it usually.
6 days left on this one, curious to see where it ends.
I've given some thought to starting a wiki article for known keyboard prices, but there are so many keyboards it'd be difficult to do. It would however provide people with a sort of rough price they should aim for, kind of like a
Kelley Blue Book for keyboards.