Is owning a RO purifier actually cheaper than renting one? I’m starting to doubt it

I always assumed buying a RO purifier is cheaper than renting because after buying, “machine toh apni ho gayi”.

But when I actually started calculating, it became confusing. A decent purifier is around 15-20k upfront.

Then filter changes, AMC, membrane replacement, service charges, installation, and if you shift houses, again uninstall/install cost.