It varies a lot from year to year. On software I probably average ~$500 a year. Hardware there been years I spent many 1000's and others I had very little I wanted to upgrade. There also a lot of overlap between what I spend on my computer for other stuff vs specifically for gaming.
I spent a lot on computer/network equipment last year but nothing to do with gaming. Last major purchases for gaming was back in 2016 for a HTC Vive and a geforce 1080. Usually I upgrade GPU every 3 years which would be this year but I might wait till next year because I have many many other things to buy because am going to settle on my first house very soon.
I do Application and Database development for a living which pays in the low 6 figures.