Don't fund with your bank account or a PayPal balance. Use a credit card or a visa debit card.
PayPal may be a pita but you can bypass them by going straight to the credit card/credit union. Nothing says you need to use PayPal dispute resolution.
As a seller I don't take PayPal or other online payment systems though. The fees are BS, and I don't like having a company building a dossier on my buying/selling habits.
Your best bets are:
1) buy from someone reputable that has been part of a community for a long time. The guy with 8 posts who joined and is already selling parts is a red flag.
2) don't spend more than you're willing to lose or willimg to need to spend a second time.
3) BE REASONABLE. covid delays are real. People have things come up. Not everyone checks email every 2 hours, and sometimes someone isn't online for a day or two.
4) be rational if there is a problem. What some people don't realize is that if something gets damaged/lost the seller doesn't magically get an instant credit to send you back. Shipping costs alone are $ these days. If I sell a part for $50, and shipping is $50, guess what. Not only do I not have the damaged item back in my hands yet, but, your damaged package I've got to wait until UPS pays out that second $50 they took for transport fees. I didn't earn that shipping money, that went to ups/fedex/usps/etc. You didn't damage the part in shipping, but, neither did I. Depending on your attitude, if I can, I may, MAY, front the shipping refund before the carrier pays the claim, IF I CAN. but there's nothing to say I have to, and demands or acting like a keyboard tough guy with a Google law degree isn't going to make me go out of my way on it.
Finally, caveat emptor, if it seems too good to be true it probably is. If your gut says something seems off, walk away unless your risk/reward appetite under point number 2 makes things worth it.