Goedman

Hi
1: you get what you pay for
2: buying yourself you can choose what you want and where to buy from. The 2 units you mention do work but are not pure sine wave inverters. I have the 2000va unit running for about 3 or 4 yrs now with the same batteries , think i was just lucky with this
3: these systems cant really be upgraded

Ok so you dont have a lot of moola, 
1. Buy a Cadac stove or a 2 plate stove that you hook up to a 9KG cylinder - Food Sorted.
2. Buy small 12v LED strip lights and wire them into each room with a bed lamp switch in parallel
3. Buy a 12v battery 100Ah around R1k (this is the most expensive part of your startup kit) Connect your LED lights to that- Lights sorted
4. Buy a battery charger. to charge the battery when EKSDOM is on.
5.  Save and When you have moola again Buy a 3KVA 24v pure sine wave inverter Around R7k (you can get the 48v as well but then you need more batteries)
6. Save and buy 2 x Batteries  R4k (if you have the 48v inverter buy 4 batteries R8k)
7.  Buy cables and connectors and install as loadshedding kit  remember this kit will not run your house, some rewiring must be done. budget around R2-3k
8. Buy solar pannels x2 R4k and add to the system- grow your system by buyng pannels when you have money
9. Batteries will have to be replaced save for this.
10. Buy pannels of the same characteristics to add to your system. EG if the panle is 335w at 40v then get pannels that are 335W at 40V. If you mismatch pannles it effects the amount of power you van get. 
 
 

I am told that fridges are a big problem for the inverter/battery scenario, because the electronics will sustain them once they are running, but will likely trip when the compressor turns on. This is because of the power peak resulting from setting a motor into motion. So the system has to be sized for the sum of all possible spikes. Which means that even a spaza shop is going to require some heavy fire power. With newer domestic appliances this is more easily done - they are more efficient, use less power (my relatively new LG fridge/freezer provably uses less juice than the old Defy (I think) that we have in the granny flat), but the deep freezes and cold drink fridges that are used in shops are probably not A+. So it would cost a lot of money for our shop owner.

There's also the matter of how these motors will tolerate a modified square wave which is what many such inverters generate.

As @Dougiedanger notes, customers are usually not aware of such details and there are a lot of fly by night dealers who don't really understand the product.

Factor in people's propensity to buy on price...

Nice topic.
I speak to a lot of my friends asking them there basic needs. Almost all of them have the following as there first priority. 
Few lights, TV, WiFi, Alarm/security. That is the bare minimum for most of them. Very few of them even mentioned a fridge.
For this application I guess a basic UPS like the ELLIES 24v 1400W unit would do good for a few hours to manage the average 2 hour load shedding we usually have. I started with the even smaller 12V 600W system.
I started 10 years ago with a solar geyser(after my electrical geyser started leaking), then few years later a gas stove(after electrical plates burnt). The last year I have been putting a lot of effort into my solar system.
The real newbie should know 1 thing I learned and that is to become independent or even just partially independent is a process and not an event. It takes time and homework with lots of planing. I have to say I loved each and every step of the process.

There are kits available for Lights,TV's,Routers only (modified sinewave inverters). I started with the 1200w model in my house and it manage to keep the lights,tv's,internet up for about 8hours +,they work well. There are some models with small external MPPT controller is you want to add a few panels
https://www.builders.co.za/Electrical/Inverters-%26-Solar-Energy/Inverters/Ellies-Power-Inverter-DC-600w-1000va-12v/p/000000000000395575?gclid=EAIaIQobChMI7da3iuLh5gIVhuh3Ch28NQjhEAQYAyABEgK5t_D_BwE
https://www.builders.co.za/Electrical/Inverters-%26-Solar-Energy/Inverters/Ellies-Power-Inverter-DC-1200w-2000va-24v/p/000000000000395576?gclid=EAIaIQobChMI7da3iuLh5gIVhuh3Ch28NQjhEAQYASABEgJ4pvD_BwE
 
FYI: I still have it and use it as a mobile power source like when going on holiday,fishing,etc

Regarding your kidneys, they pay more for the right one . Lol . Look at a once off purchase on the equipment and not training batteries etc. Decide what youre going to run on the system and will it be within the ratings of a 3kva inverter. It is a good idea to find your day and night consumption to size your battery pack. But your biggest bang for buck will be to cut back on wasteful usage, and possibly a solar geyser or conversion if you don't have yet. DIY can be fun and save some $ but assuming you don't blow thing up in the process. But this is a great place to ask questions before the  costly magic smoke is released.

Thanks @gabriel, don't feel bad, this is such a steep learning curve for most of us.
That is why a forum like this helps a newbie like me avoid some of the most expensive mistakes.
I catch water from the roof and balconies and up to now only used it in the garden. We have been spoiled with dependable clean water from the town council but lately there have been some unplanned disruptions in supply. Now I am doing some research to learn how to pump the rainwater into the house on those days that we don't have any water. When we get lots of rain (mostly in the winter for us), I might want to use that from my 10000 liter tank when it gets full enough. As a pensioner it is also important to save some money wherever I can.
I am still looking for a nice diagram to show how a system like that could work.
Thanks to you and everybody else on the forum that shares so generously for the benefit of others.

I recently invested in a nice Makita hammer drill, and some SDS+ bits. My only regret is that I didn't do this years ago. If I just think of the many hours working with an impact drill. Just put a nice 22mm hole through the middle of the brick and put in some proper conduit.
Of course it helps that prices came down quite a bit. Bosch makes a nice entry-level SDS+ drill that you can buy for under 2k on Takealot now. I got the Makita for 2k.
The other thing I got was this pipe/electrical detector. This thing is more accurate than some more expensive alternatives I've used. I got this one more for plumbing work (Western Cape, big drought... you know :-) ).
Perhaps a bit off topic, but having good tools is just so satisfying.