You can put up as many middlemans as you want, in the end you have a seller "I did send the goods,where's my money ?" and a buyer "I never got the item (or it was broken), I want my money back !! ".
Dunno, sitting in between those doesn't sound to comfortable.
Think about ebay, as of buying buying on a flea-market, you never know wether the stuff works, has been stolen, is conterfitted and and .... in the end you just have to use common sense and be careful.
Bout reproducing HW, most parts aren't available at any cost, product may not confirm with current legistalation (RoHS being just the tip of the iceberg) and the market might be much smaller than you think. 100 CVs changing owner on ebay per year does not form a viable market for new CVs.
