Ninja Girl

https://powerforum.co.za/profile/6102-ninja-girl/ If you reveal your location I'm sure there will be offers from those on this forum capable of doing this work
(Just add your location in your profile) 

@Ninja Girl what inverters do you currently have? Will you be moving them with you?
 
the reason why I am asking this is that 
1. a pylontech US3000 is around R20000
2. A good inverter of 5kw is also around R20000 If you buy a Mecer it is around R12k 
Is the rest of the cost the installation, this sounds very steep, The Instalation and wiring and COC should not be that high. It will take a good electrician about half a day to split your DB and wire the inverter and batteries. At R500/ hour that is R2k plus say R2k for the certificate which is very high, plus around 2-3k for material depending on the distance from battery to db. I know people on this forum is going to kill me but charging more than R10k for a basic instalation is raping the customer. 
The extra money could buy you another US3000
just my 2c

This setup is a bit unbalanced. The 1 Pylontech will only allow for a constant discharge of 37Amp. During a power Failure you should ensure that loads are kept low. The electrician should ensure that the Critical loads stay below the limit of the battery. 
Normally your 100ah batteries are not the best options around, If you can afford the Lithiums, you would be better off in the long run.