Was it Independent Living, or Assisted Living? The cost difference is huge. "Mobile" could be either.
Assisted Living. By "mobile" I meant she could walk, with a walker at least for a while. But she was rather incontinent, and had demenita, and died at 93 of just old age. Could not eat fatty stuff (gall balder) but liked salad and steak and was a industrious faithful worker, despite migraines, yet a mother of 5 with her faithful welder-husband, thank God for both. I am the one who gave her some headaches)
I was going by what I recall being told by older sister who handled things, but I checked now and prices per month are, Shared Suite $3,346; Private Suite $4,015; Studio Apartment $4,349 Which is less than the monthly average of $6,450 per month in Burlington, MA. - https://www.seniorly.com/assisted-living/massachusetts/burlington/sunrise-of-burlington
Thus the base price averages about 47,000 a year, though,
"In addition to the cost of "room and board," many communities also charge separately for care. Most large sized communities like this typically charge additional care fees. Communities will use a Points or a Level of Care system to determine the care related fees. https://www.mylifesite.net/blog/post/what-does-assisted-living-cost/
So I really do not know what level Mom had, but it is more expensive in MA. As with eternity, location is everything.