Tirerack sells TPMS separately at $120 each or $480 for a set of four sensors. Currently, the cheapest 18" rims for a Model Y are the
MSW 40 (@ $198 each) and the cheapest winter tire for this rim is the
Cooper Discoverer at $200 each (which has limited seasonal availability right now).
So the TireRack price would be $800 (rims) + $800 (tires) + $480 (TPMS) = $2080. You could get a better price on the TPMS on eBay (or wherever), but I think you'd have to have the rims and tires shipped unmounted (i.e., separately) and then install the TPMS before having the tires mounted and balanced.
The 19"
Tesla winter tire package (not available until Fall 2023) is c. $400 more at $2500 and includes TPMS.
The 19"
TSportline winter package seems to start at $3300 before purchasing lugs and TPMS.
The 19"
WheelWiz.ca rims seem to start at $205 with no TPMS or lugs.
I need an all-weather/winter tire package for my MYP. I was hoping to buy some used, dinged-up rims and TPMS on eBay or craigslist and have Costco slap some 18" or 19" allweather tires on them, but notwithstanding the popularity of the MY, there seem to be
very few used rims for sale at a reasonable price. I'm generally fine with purchasing rims, tires, and TPMS separately and dealing with a separate mounting and balancing process, but at some point, the amount of money I would save does not outweigh the time and effort necessary to lug around 100s of lbs of tires and rims.
Basically, IDK what I'm going to do yet.