Buying a RO is not a one-time cost. It becomes AMC + filter + service

I used to think buying a RO means one big payment and then sorted for years.

But after actually looking at the costs, it feels like the machine is just the entry fee.

First you pay 15-20k for the purifier. Then after a few months someone comes and says sediment filter change, carbon filter change, membrane weak, UV lamp issue, TDS controller, service charge, AMC, extended warranty, etc.