Absolutely not.
Take it to your grave with you that is what I say ;-)
On a more serious note, I believe that if you're not using something, and want to sell it, it should be at a price you yourself would have liked to pay for it.
I only ever sell things to people I know, people who are real users and are not buying them just sell on at a profit.
I then sell at a price they want to pay and I'm prepared to let it go for, usually many times below market price.