I am prepared to invest my time and plenty of money in buying a mining PC, and maybe buy some coins, but I want to make sure that there is a chance I might get the money back from my investment, and the best way to make sure is to ask if you personally held some dollars or euros in your hand after changing some BTC's obtained from mining.
I did mine altcoins, one of them was Monero, many years ago (mined some, bought some). I did sell some for Bitcoin, I did exchange Bitcoin for fiat. I didn't actually touch that fiat because I've spent them as bank transfer, but it's good enough I hope.
But it doesn't matter. The mining profitability depends on your
electricity price now and the
market (which we hope it'll recover, but the truth is that it doesn't look great). And it depends on
you. If you want to hold forever, you do that. If you want to spend (sooner or later) you'll spend, there are plenty of way nowadays to spend Bitcoin.
You better start with your electricity price, the specs of the hardware you want to buy and a mining profitability calculator.
Also since you mentioned "a mining PC" you may want to move this thread to
altcoin mining.