I don't follow prices of Model A parts very carefully, but a few years ago I went through my parts boxes and dug out four or five Tillotsons in various states of completion, mostly together. I think I was asking $45 for the whole shebang. Not one person responded, not even a request for only one carb or parts they needed. Nada. I have since used most of them up repairing other people's Tillotsons.
Maybe things have changed since then, but I considered these carbs as having little or no value to the collecting community. Perhaps RNOS Tillotsons still in the box would command $100 prices, but based on my sad selling experience, any condition less than that means you'll only get what someone else is willing to pay, usually less than what you expected.
Marshall