From my POV, here are a few things people should consider in here:
1) Post the important specs of what you are selling! If you don't
know, find out. A lot of manufacturers keep specs on their sites of
even the old stuff.
2) Post prices on new stuff under Nashbar and other catalogs--we all
know the cheapest places and coupon codes.
3) A good starting point for used stuff is half of retail price. We
all get tired of seeing the same damn used stem posted 27 times at
nearly full retail price. Try jumping the flaming hoops of the Ebay
process if you can't accept this.
4) Bike shops--same deal. You're better off putting your stuff on
ebay. We all know what your stuff is worth. Buyers, try your LBS if
you need a personal level of service. Exceptions include Dan
Donnelly's fantastic prices and service. I had excellent luck with
Ted Prahl as well.
5) Accept personal checks. In ten years, I've never had a check
bounce. The whole point of this is to get rid of your stuff with zero
service fees. Thirty seven cents for a stamp is a lot better than
what PP is charging!
6) Accept trades. Have fun with it.
7) Give stuff away for the cost of shipping. Your seven speed stuff
is better off on someone's beater than it is in the landfill. There
are also local Recycle-a-bike and Critical Mass charities than can use
your old stuff.