All is not lost. You can use an auction service but it can get very expensive. Not too bad if the parts are rare. Go to www.rinkya.com and check it out. I have used them to buy stuff before and sometimes you can get a great deal. However, be careful of all the fees.

If you are buying large items like engines, bikes, etc... you can use a company called: http://www.isibike.com

Hope that helps.