Not heard of anyone on here mentioning an alternative. I believe the units cost around £70 for the part and I assume the rest is fitting and registering the new sensor to the bike electronics.
They are rather fragile and can get damaged, not as robust as you would ideally want on an adventure bike, but I do find them reassuring.
expensive but worth having imo,only last week on the way to work,the tpm monoriting for the back tyre started to flash a warning,stopped and checked and sure enough large nail in tread,took it easy and got to work ok.so worth fixing properly i reckon.