Firstly, driving and hearing are two completely different things and aren't comparable.
Secondly, more money, even vastly more money will not guarantee you a better sound although it will probably assure you more headroom and probably more features. I've read write ups of blind tests of multi-£10K systems against £300 Yamaha receivers and the listener could not hear a difference. Speakers will sound different (sometime a lot, sometimes not) but hardware is unlikely to or it'll be so subtle that you'd need ideal listening conditions (e.g. not in a car at the very least) to discern them.
Of course not directly comparable, but the principal is the same.
Actually, no, the principles are not the same. Maybe you should read up on psychoacoustics.
I wish I couldnt tell the difference between £300 and £10k, then I could save myself £9.7k. I wish a Fiesta did 150mph and look the bollox, and I could save myself £20k.
And if you did do some reading, you'd understand that just
knowing that the equipment you are listening to costs £10K will, without a shadow of a doubt, influence your opinion of what you are hearing and how good it is. This has been proven time and again. What has also been proven time and again, is that generally speaking, most well designed digital equipment sounds just about the same as any other well designed digital equipment no matter what the differences are in prices and, even when there are differences, they tend to be very subtle.
That's not to say that spending more is always waste as it's not; there are other reasons to spend more money besides the non-existent "better sound" that include build quality, longevity , more power and headroom, more functionality, nicer aesthetics, and better support.