Yes under most circumstances I generally did and still do. If I have any issues that anything more than a well designed mains cable can't address then I prefer to tackle the cause of the problem. All my cables are reasonably priced custom made cables with both foil and braided screens connected to earth at both sides of the cable in a BS approved fire retardant outer covering so are suitable for in wall use if so desired. They are of sufficient size to carry more than enough current and are still flexible enough to be easy to route and conceal. I don't think that you need any more (They are almost certainly overkill as it is) and I also don't think that it follows the more you spend on a component the more you need to spend on a cable.

I am not sure why gauge has been selected as a particular metric in this case however as 18 gauge is more than adequate enough to carry more current than the connectors are rated at and the components can actually draw. There are much more vital metrics to judge a cable on than gauge (Provided it is adequate which in this case 18 gauge is) such as capacitance, impedance and resistance. I defy anybody to tell the difference in real world performance between my cables and some of the more esoteric ones in anything more than looks and price alone. I can't even tell the difference between mine and the supplied standard ones if truth be told.