"Period correct means" whatever you want it to mean.
For people with nostalgia for their teens/student days, unless their surname was rich and famous or their parents funded whatever they wanted, that probably also implies a time when they did not have the cash available to buy the most expensive system available at the time. If you consider >90% of teenagers "poor", so be it, although I'd use different language. Your first car probably wasn't a brand-new sports car either...
Of course, others specifically want to create that dream system that was unobtainable back in the day, or a range of hardware where back then you had to choose. I may have had a GUS Max back then I was proud of, I certainly didn't have the GUS, AWE64 Gold, PAS16 and a slew of other cards, plus a few Roland and Yamaha MIDI modules and Wavetable cards (and the mixer+patchbay to hook them all up) that I have now. I also wasn't into soldering my own cards together back then. It's not all nostalgia 😉
Tbh regardless of available cash, just throwing money at a problem defeats half the challenge and enjoyment. Yes, back in the day you could get a great frame rate buying the P3-450 the day it appeared in the shops - but it was a damned sight more satisfying to equal that performance overclocking a Celeron 300A you paid a fraction of the price for. Same today - if you have money to burn, you can go to eBay and get all those perfect parts. I have a nice job in engineering so am hardly 'poor' - I could choose to do exactly that. But I get a lot more pleasure out of finding spending the time and effort to find gems in piles of unsorted junk, which also lets me spend my money on other things I enjoy.