While I agree that the three-legger is a desirable collector coin, IMHO, it's way over-priced; this, simply because many coin folders have a hole for it. There are many scarcer Buffalo varieties for which no hole exists. At any major coin show, there are numerous three-leggers resting in showcases. The supply of these is apparently sufficient to fill the holes. I'm surprised that folders lack a hole for the 1938-D/S, considering how plentiful they are.
It's not so much that we "naysayers" reject the variety, methinks. We are more inclined to reject being told what coins to include to make a "complete" set. If the abum makers suddenly decided to create a hole for the 1909 VDB double-die, how would that go over with collectors? Not well, I expect!