Is This Allowed?

Not allowed. They let it slide for modern bullion from the big guns, but not this.

Below, where it has the coin's stats, the cert.# says 5031. This is a # exclusive to PCGS Merc. 10c.
That's how he's getting around it.

Going through his listings he does have multiples of the same coins, but each one is photographed separately, I wonder if he is including the other coins and will just end the auction early on them if someone orders a multiple coin lot?

Doesn't matter what one thinks of the practice; it's prohibited by the rules. Requires you to buy the slab and not the coin, which goes against what we stand for.

This is why I keep away from ebay. Never know what you'll get. If he does not show the actual coin, might get something different.

justcarl, the seller's got almost 11,000 feedback at 100%. I think you'd be safe saving you paranoia for someone else.

I think they let it slide for moderns but I do not think they do for this.

I've purchased a few coins under similar circumstances on ebay (e.g. MS64 Washington Q's and MS66 Jeffersons) and invariably, the quality of the coin is below the one pictured. My interpretation is that sellers want to sell coins easily and with minimal effort, so they "commoditize" coins graded from original rolls by selling them 20 at a time on ebay. As we all know, coins within a grade are all unique and not every coin in that grade will appeal to every collector.

I've also noticed some sellers say they won't accept returns of graded coins because a third party has decided the grade. Problem is, the third party doesn't select the photos supplied for the auction and lots of things critical to the appeal of a coin are missed, even with photographs. I don't buy from dealers with terms like these.