Pay Pal

Three or four different markets for three different categories of parts-

Swap meet- large items that are better suited to hand off physically without boxing and shipping. Some high dollar items for the captive market of the meet. Small, inexpensive items where shipping could kill a deal.

Craigslist- again, larger items that are a pain to ship, and things where shipping would kill a deal. be prepared for BS. Things that are not practical to keep loading and unloading to take to swap meets. Do not give out personal phone number or personal email unless you want more junk/spam that you already get.

FxBO- items targeted to specific needs, appealing again to a captive market.

ebay- items that you can pack and ship effectively, that are worth more than the shipping cost and labor involved, and items you want to try to expose to the largest possible market to get the beat price. Be prepared to do your boxing first, so you can have a correct shipping cost.

If you don't take paypal you are missing out on a very large potential market.