The answer to your first question is, don't trust Amazon Marketplace.
There are a hell of a lot of (american) sellers, who try to push prices
beyond any reasonable limit.
To give you an example, I've recently watched a book by Michael
Kenna, which was listed as oop on Monday, go straight up from 30$
to more than 500$ until the end of the week - by the same sellers,
who had offered it for 30$.

Unfortunately, some private sellers think that these prices are can be
fetched indeed and start to offer their own books / CDs at the same
level.
The only effect is, that the whole market gets mixed up and
(hopefully!) no one is stupid enough to buy these ridiculously
overpriced items.

To answer your second question, you can sell it for as much money,
as someone is willing to pay. But don't be surprised if the offers will
not meet your expectations. We're obviously living in a recession and
in the last year, even many scarce items failed to sell on eBay for
more than 20-30$. (This doesn't count for bootlegs and counterfeit
Varese Club CDs! ;) )

Good luck,

David

coma, June 19, 2011; 1:46 PM