Thanks for having a sense of humor.
I think the idea of seeing Curve>$500 is what doesn't fly.
As for an asking price, that's for you to decide. Yes the accessories are expensive, but lose a tremendous amount of value second-hand.
Prices on eBay are generally higher than prices on these boards due to a number of factors, one of them being that here you don't have to pay to sell, but you also don't have eBay and/or PayPal backing the sale.
Good luck whatever you decide,