I have bought many excellent items from E-bay, and several duds. However my worst experience was a silly 2pound adaptor from the uk that cost me around $30AUD postage and never arrived. The seller had a high feed back percentage but with over 11,000 items sold had rather a lot of negatives I never bothered to read before. Turned out he didn’t care about overseas transactions and retaliated with "bad buyer ... liar ... see other 11,000 positive feedback..." as standard practice to any problems. The item never arrived, after giving up on communication I left a negative feedback to the effect " ... see other negative feedbacks they do matter". The result was he reported me to E-bay square trade as having received the goods and claiming I hadn’t in order to get a re-fund... funny my small country post office hadn’t seen it either! To my absolute surprise, e-bay terminated our account despite a 100% positive feed back ... turns out sellers who turn a good volume over are more important to e-bay than honest buyers!!! I wouldn’t bother relating this other than it seems to happen rather often, and E-bay its self is such a giant it seems to be a law unto its self, with no accountability to anyone.
Okay off the soap box. Look around charity shops, some of my best bargains have come from them, plus you can handle the items first. Also watch the for sale ad's in your local paper, if they are selling dark room gear, chances are they have an attic full of old camera stuff.