TLDR: Used TPMS sensors are a waste of money, their batteries will run out.
Seen many threads from people selling used TPMS sensors. This is a WARNING for the buyers. All TPMS sensors i've seen from Toyota are battery powered. So when the battery runs out, you will have to change them.
According to many local Tire shops who sell sensors, these sensors tend to last anywhere from 3 to 5 years, then you will have to change them or upgrade to a battery-less sensor.
Basically if you are buying a used sensor, and it already has a couple of years, you will be having to change them very soon after.
This thread is just to help a couple buyers and help them not waste money. As to the sellers of this type of item, I am by no means trying to say selling these sensors is a bad thing.
If the sensor's battery is replaceable, that is a whole nother story.
Hope this was helpful.