Used instruments pricing

[Angelic Layer]

http://www.prepal.com/manufacturers.htm

However it doesn't take into account of condition of the instruments.

[ChrisMcCoy]

That's a great site.
The other thing to keep in mind is that some e-bay auctions can get you a really good deal when the auction goes no reserve and the opening bid is low. In some cases, when the demand is low for a particular item you can end up getting a really good price on what you're looking for, especially if no one's bidding for the item other than you. :D