I don't think it is an accurate comparison. Tiny pearls are much, much cheaper than huge pearls. They also seem to have sharper luster. I think it is because there's just more "curve" to them when they're so small. To compare fairly, you would have to put pearls of the two different qualities but same size side by side. In other words, if you put, say 6mm pearls of the cheaper, lower quality ebay ones and the higher quality, more expensive ones, there would likely not be all that much difference in quality or price. However, if you put 10 mm cheap ebay pearls next to 10 mm high quality pearls, I bet there is no way in the world the cheap ebay pearls would look anywhere near as good as the high quality (and much more expensive) ones. Quality and price would differ much more between the two. Just my opinion, though. Experts, right or no?