kmhamel: Is the encoder wheel machined/customized at all, or is the shaft made to fit through the stock part?
If not:
Encoder: say its $20 each if you buy a hundred based on ~$33 list price part
shaft: milled from round stock, threaded on the end, chromed, probably $20 each if you did a hundred
Plastic encoder housing alignment widget - no clue, say you could order plastic stock and machine 100 for $6, probably cheaper than having a mold setup.
fasteners, wire header, wire - prob. $4 per set.
No expert by any means, and I could be way off, these are guesses.
so by my back of the envelope calculation, the cost of the assembly is $50. probably have to sell it for $80 to $100 is my guess. more if the encoder wheel has to be worked on. Numbers probably look a bit better if you do a thousand.
I don't know what kind of installed user base the u360 has. I'd pay the price of the stick or more to get this capability, but its steep. Pretty soon you have the guys out there that figured out that some rotary games have 12 clicks, 10 clicks etc. and it's hard to satisfy everybody.
I'm certainly in if it becomes available. If not, Kmhamel-consider doing a drawing of the replacement shaft, the widget and a parts list, and you can be famous like Bender with the top fire mod. And I can turn one out when I get my lathe.