So because we cant mount batteries on wall, prefab mostly they'll have to be on the ground.
3.2KW + 2.5kwh battery + 4 panels = R54k
5KW + 5kwh battery + 4 panels = R65k
Essentially a retirement home so small but they do have days were there is no eskom power but sunlight is very good.
Is that the second-hand price? I thought he was offering a deal...
Since it's on the ground anyway why not just get a trolley system like this:

Mecer 2kVA 2kW Lithium Battery Inverter Trolley with 100Ah Lithium-ion
Mecer 2kVA 2kW Lithium Battery Inverter Trolley with 100Ah Lithium-ion Battery and 820W MPPT Controller SOL-I-BB-M2L and other Mecer products available at FirstShop South-Africa. Price, availability and reviews for Mecer SOL-I-BB-M2L

2 kW / 2.5 kWh + 2 panels = about R 20 - 25k max.