But the difference is, collectors usually have full time jobs and lots of other commitments. Proper coin dealers do the same kinds of things daily and they gain a big experience on the kinds of things people want, and also how to price and grade their coins. They usually keep a good general stock too. Anyone can be a 'dealer' on ebay, but it's likely to be a very ameteurish hobby affair unless you have an independant regarded point of sale such as a shop or a website. And to be a proper dealer, some kind of dvertising is good too and you need punters and contacts. It would be hard to be a coin dealer just using ebay to buy and sell.