I think your calculation is not correct, as the Self care Plan is RM 320 / year right?
So it should be RM 3,200 + (RM 320 x 5 years) = RM 3,200 + RM 1,600 = RM 4,800
Rental is as per your calculation, comes up to RM 5,040 and the difference of RM 240 can consider as extra warranty, as LG Puricare is warranty for 7 years if taken under the rent-to-own plan.
I have since decided to move from Aquaphor to the LG Puricare due to the following reasons:
1) App Connected and real time monitoring of filter health, with Aquaphor I just change it every year and the filter cost is more expensive compared to the LG.
2) One Touch Self Cleaning initialisation or machine cleans itself every week (at my preset time, can be done using app), there's only one other brand on the market which does this but doesn't have app and is more expensive.
3) Compact dimension, can be place on counter top and flush against the wall ( I got WD516AN in Navy Blue) and looks elegant enough
4) Hot Water Temperature can be selected at 40DegC, 75DegC and 85DegC
5) Tankless Design for both hot and cold, which translates to no microorganism breeding ground + not needing maintenance cleaning.
6) Self Service Filter change, and filter delivered to doorstep at no additional cost.
7) Cost Savings from Energy Saving (No Tank so continuous standby heating or cooling)
8) Filter Send to doorstep at no additional cost
9) Not RO Water and water quality actually tastes better than Aquaphor filter
10) The Auto Up Down feature can be switched off, important as my parents find it annoying
11) Inverter Compressor = very minimal to absolutely no noise when its working
12) Installation done by LG Malaysia Team and Warranty also by LG Malaysia, hassle free.
If you are considering a Hot, Cold or ambient water purifier dispenser, LG is one of the smartest and affordable option available right now.
I just installed mine on 1st Sept 2023 and if you looking for promo, can PM me

The app interface looks something like below:
