I've been selling my artwork on eBay for a little while now, and have been astounded at the low prices that some of the artwork actually sells for.
I admit there are a lot of opportunists who try to make a few bob by posting stuff which they purport to be art, but when you monitor the sales, you see that they soon run out of steam and stop posting on the auctions.
I have seen some amazing art sell for peanuts compared to the galleries, and for the life of me, can't work out how the artists can sell it at such a low price.
I haven't made my fortune by selling on eBay, in fact I probably sell at a loss when you consider the time it takes to e-mail the winning bidder, bank the cheque, wrap the art, go to the post office etc, but I now have a kernel of customers who buy from my website and want to be informed whenever I produce new work.
If I was a small gallery owner I would watch what is happening on eBay because in one respect I'd be concerned about losing business, and in another respect I would view it as an opportunity to buy first class work at an exceptionally low price for re-sale.
There are some forums on eBay where art pricing etc is discussed at length, and I can say that the current low prices will not last forever. All the artists are aware that they cannot continue like this for much longer, but it only takes a couple of sellers to put work up for next to nothing and a lot of lemmings will follow.
So, in answer to your original question. Yes, there are some excellent bargains to be had from eBay. But don't tell anyone otherwise they will all be buying from there
You may want to try looking at the UK Artists Self Representing category. That's where most of the artists ply their trade. It's a relatively new category, and will take a little time before it starts buzzing.
Here is a link to it if you are interested.