The most expensive is probably the CO2 setup. Could get away with DIY but You are probably looking at about R1,000 to R1,200 for a bottle, regulator, needle valve and guages. Possibly more. Then there's the light. As for the rest, it's mostly standard equipment. One advantage is that you don't need so much flow.
I have seen VERY VERY nice planted setups without any expensive equipment. But you'd have to ask those guys how they did it... I could never get my plants to flourish without CO2 yet other guys have awesome growth without CO2. And don't listen to any watt per liter BS when it comes to lighting. You need a lot of light for most of the nice plants. You do get low light plants though, but IME even those do better with a lot of lighting.
Well the CO2 thing isn’t really needed any more. The only reason why you add the CO2 is for the carbon molecule and new technology allows us to add a liquid carbon.
One of my tanks is a completely low tech setup – well except for the lights as I am running 3 T5s on there. The substrate is completely home made and the plants are mostly cuttings.
On my 800L cube I run 2X150watt 6700K MHs as well as 4X CFs, with full on CO2 injection (due to cost of liquid carbon for tank this size) and an Eheim professional3. The substrate is actually to rich and is causing some issues with murky water. With the replant I plan on redoing the whole tank is it is being over grown with crypts. The substrate will also be thinned out as well as capped with pool filter sand.
Regarding where to get the plants from, well now that is a really k@k one in SA. We have had one or two really good plant shipments come in but not much. In fact it has gotten so bad that we are awaiting our plant import permits to arrive this week. We should be landing 4500 plant next week for sale to pet shops.