>most sellers don't accept them
That's not true. Very very few people are willing to pay by cash, so it's basically paypal or nothing, and eBay requires paypal accepters to accept credit cards.
I can't speak to the price, except that I find ebay items by using google product search, and price is king.
and thats another thing, thanks to eBay used things end up costing almost as much as they do new. In fact about a year ago I was bidding on something second hand, and the final price ended up being about 15% more than the thing cost new(both online and in stores).