[AMBST95]

I wouldn't expect them to narrow, I'd say it's a combination of a couple factors. First, the auto on the yellow looks to be nicer than the others, has sharp contrast, and is in pen. The full batting pose is in pencil which will not hold the same kind of value. This other pose 181 has paper loss on the back and is trimmed which I would think hurt it's value. The cards are rather equal as far as rarity, but the big differences are the clarity, implement used, and damage to the item being signed. It looks like price is reflecting this too.