I like buying coins off eBay, there are good deals to be had but always keep your head on a swivel. I noticed a new seller that had familiar washed out garbage photography and had a suspicion it was the same photography as Auction Kings. The only coin I've ever purchased from Auction Kings was a NGC graded slab. Not much room for buyer error there. Tonight I saw some similar photography, and sure enough, I searched my purchase history and Auction Kings is now CoinShopArizona. Just a heads up, I'm always amazed the amount of volume they do with their absolutely deceptive photographs.
But eBay's been requiring sellers to post actual photos of the actual coin* for YEARS, and now they're even requiring sellers to pick a grade for raw coins! Surely that's more than enough protection for buyers. * except in cases where, well, I don't know exactly what the exceptions are, but there are apparently lots and lots and lots of them.
I think MORE information is always good. As for sellers having to grade....give me high-quality HD or 4K pics and I can guestimate the range most likely. If it's a raw coin, you know there's going to be a range from any non-professional "grader." A 48-hour notice that one is returning the coin upon receipt would also equalize things.
I am an eBay fan, but the lack of quality control makes me very cautious, so I am extra careful to check the seller by percentage (100% only) and length of time he has been a seller on eBay. I've learned the hard way without satisfaction from eBay! Buyer Beware...
I have not noticed sellers having to grade. In fact, eBay doesn't allow listings to be posted by grade in the title unless it's PCGS, NGC, ANACS, or ICG. At times that rule falls between the cracks, a SEGS or PCI will slide in there. They do require sellers to describe in their listings details whether the coin is circulated or uncirculated. And that is not always accurate either, it's an opinion.