I have spent many more times that on equipment and was sure I had made real upgrades until I did some blind, level matched tests about 10 years ago when I stopped work so I had a slightly smaller income and much more spare time.
To my amazement the sound differences I was sure were there disappeared when I didn't know which I was listening to and the levels were very accurately matched
My dCS DAC sounded sufficiently similar the DAC in my digital recorder I couldn't reliably tell which was playing, so I came to the conclusion at the time that even if there was a difference it was negligible.
I am an engineer but had really fallen for the idea that if you could hear a difference that you couldn't measure you were measuring the wrong thing, but looking into hifi in the same way I did racing cars it seemed obvious that since on the electronics side we could measure everything there is (signal level, frequency and phase) to a level beyond the capability of our ears all electronics and cables can be measured sufficiently thoroughly to absolutely
know whether they have audible shortcomings.
Checking out the measurements of the dCS and my recorder confirmed later what I had heard, they both have distortion and noise levels below audibility, so no surprise in the end even if there had been at the beginning.
OTOH speakers vary markedly and the ones I have here which vary in price from £800 a pair to around £130,000 all sound obviously different to each other.
The other things making a huge difference to the sound is the position of the speakers in the room, room acoustics and the location of the listening position.
Things making small but audible differences are, in my listening tests, the chair I am sitting on and the acoustic properties of its upholstery, my favourite comfortable high backed leather recliner being one of the worst for sound quality.
I still have a pricy system because I had bought it before I used my own engineering logic to question my past (erroneous) opinions, the most expensive speakers are still my favourites and are in the best room location and most listened to, but I no longer use quite such an expensive dac/pre/amp package and still enjoy it for several hours a day.
My view now is that if one hasn't positioned one's speakers optimally in an acoustically benign room with an optimised listening position the money spent on the rest of the system was more than necessary and expensive kit pointless.
With a record playing system the cartridge, isolation and, again, location of the record player make differences too, I have four record players and they all sound different. I don't listen to them often though.