The issue with the cost of sport bikes is 2 fold. One, the technology that goes into them is not cheap. Two, everything is more expensive. This is pricing most people out of the sport.
There isn't much to talk about on point two but, per point one, remember, back in the 90's when the suspension that came on the bikes utter sh*t. The early 90's caused the GSXR to put on almost 100#s over the course of 5 years. The 96 GSXR came out and all was better again, but the price difference was also there accompanying the massive redesign. It's been an arms race ever since and the price has kept pace with the technology. Some of the stock suspensions now are as good as the elite race suspensions of just a few years ago. That type of progress is not cheap.... but it is completely unnecessary. Even at a track day.
I have been riding old bikes for a long time. I run stock suspension, with the correct spring for my husky size. Other than that, their isn't much to be done. There is no need. We have this ever present desire to have the best money can buy, without even thinking if it's really necessary. How much is that quick shifter going to help you be a better rider? How much are those rearsets going to make you a better rider? I can see suspension work, a simple ignition upgrade and comfort pieces. Outside of that, I don't think the upgrades we pour money into make that much of a difference. The average rider can spend 10k in upgrades on a bike and I am not convinced that they will be any quicker (or have more fun) without becoming a better rider first.
Unfortunately, in general, we buy bikes because that have shinny things on them. The Brembo brakes on the new GSXR arene't cheap, but I don't think they add much to stopping the bike better in the hands of even an experienced amateur. Adding a new Brembo master cylinder to your braking system, probably isn't going to improve anything. It will feel "different" and that may give you more confidence to brake later and harder, but you had that ability before you bolted the part on. You just didn't try it. So much of what we do is mental and has little to do with our equipment.