I think if you can have such a device for under 100 USD then there is a good chance that it will catch on.
Yes indeed, but even if the price of such an ASIC was well over 100 usd it would sell itself easily. Gekkoscience Compac F offers the same kind of performance (approximately) and can be bought for between 250 and 400 usd depending on the reseller and the time.
It doesn't have to be so cheap to be sold IMO.
In my opinion, the real advantage would be to produce ready-to-sell PCBs and offer DIY kits if you want to sell cheaply, but that would limit the customer base even more.
In any case, as OP said, it's not at that stage yet

So, should I invest the time (and money) in this for you? Or is this a niche product? I have no idea what the retail price will be in the end, but the pcb hardware and assembly should not be much more than $50, add to that a margin the the sales & production, an included cooling solution (say $5 for the heatsink and another $2 for a fan, $x for 2 small 3D printed clips to mount everything) and that should be it.
Its too early for resellers, first comes the manufacturing, and I've sniffed enough leaded solder and flux in my life to even attempt doing it myself Wink