I seem to remember about 3 times when I've noticed it, so there may well have been more. I don't look on ebay for coins that much. These days, everyone can sell anything directly can't they, and in a way that's a pity for all specialist trades because it makes it a little more difficult for them to acquire odd little items. Thankfully people generally can't be bothered to catalogue and identify whole collections for ebay, and there are some that don't bother, so the future is still rosy for coin dealers! I mean 50 year ago if you wanted a shirt, you'd go to a tailor. Now you can get one on ebay....Come to think of it, you can get one in a Supermarket or even a petrol station too! In fact everywhere you go you get bombarded with things you didn't really go there for! I digress.