Whichever system you buy, at whatever price point, the appropriate cables will help it to perform at its best. There’s no black magic or ‘weird science’ to this phenomenon, by the way, whatever you might read to the contrary. Better-quality audio cables simply relay more of the musical signal than cheaper or ‘freebie’ wires.
So, how much should you spend? Most specialist magazines advocate spending a total of 10% of your available system budget on cabling to optimise its performance – so, around R2000 in a R20 000 hi-fi. This should cover speaker cabling, to link your amplifier to your speakers, and interconnects, to hook your source component (or components) into your amp. Choosing interconnects is a relatively straightforward process – the shortest possible length of an appropriately priced link will give optimum results – although some electronics manufacturers recommend specific brands, as they believe they give better results with their kit, so it can pay to do your homework.
Speaker cabling, meanwhile, should be of equal length wherever possible, since this ensures an even ‘load’ is presented to the amplifier. You should also aim to use the shortest possible lengths you can, taking the most direct path possible from amplifier to speakers, and avoiding any kinks, coils or other undesirable twisting in the cable itself.
That aside, you can find that speaker cables have a specific tonal character, which can help to fine-tune the balance of your system. Cables with a high silver content, for example, tend to sound tonally sweet, while substantial solid-core cables often provide a more powerful sound. However, there’s no hard-and-fast rule here: the best option is to ask to audition some suitable cables with your proposed hi-fi system, and judge the effects (or lack of them!) for yourself.