Good question/scenario
I have faced a dilemma from time-to-time at this forum in a related way. Let me explain:
People have come here seeking information about an old drum set they found or one they dug out of Grampa's attic, etc. It would be easy to mislead people in some instances.
Awhile back, there was a person who joined up to ask about a red sparkle drum set that is wife had found at a neighborhood yard sale for $30. He wanted to know more about it -see what it might be worth. Well, turns out it was a complete Jazzette kit with the matching Supraphonic. It was complete with the cymbal stand, snare stand, pedal and hi-hat. The only thing missing was the second cymbal stand. Eye Ball
Needless to say, being a Jazzette fan, I went nuts! I told him everything I knew and mentioned that "If you ever decide to sell it, please allow me first refusal" -like I expected the guy to contact me. Well, he DID contact me Eye Ball and so I shot him an offer. I knew the offer I made was relatively low. I knew the set was worth more -and I told him so. But I also knew what my budget was and I threw an offer out on the table that was do-able foe me. He accepted it, happily. He just wanted to get rid of it and didn't want to wait around for an auction to draw to a close. We hooked it up and that was that. Thanks to his wife, that $30 yard sale find turned into quite a return on their investment. And, I got a Jazzette kit!
The moral to the story is that, as long as everyone is happy, and get what they want/expect, then that's all that matters. It's not ripping anyone off if they set the price.