Guilty
You do research and try and price things with the 20% ebay cut at the end in mind. If its high, I am easy to work with and generally give 25% off to board members off ebay.
I one time bought a scrapbook on ebay with two 1923 Rose Bowl tickets inside. I tried to do all the research I could and never found a record of one selling so ultimately decided to put one on ebay for a super high price (in my mind) $3k. It sold in an hour. I figured I would go higher with the next one, $4k. It sold again. I was pretty proud of myself (the scrapbook was $125) until I got an e mail the next day asking me to please contact the winner and offer him $8k for the last one I sold. So I sold $16k worth of tickets for $7k thinking I had overpriced them.
Point is, I try to be reasonable with prices and I sell a ton of stuff, but you can always go down a bit, but never up once its gone
Rhys