Ultimately, there’s very little I can do at this point. I can try to take a $34bn company to small claims court. I can wait until PayPal takes the money out of my account (assuming I even have $900 in my account, which is rarely the case) and then file a complaint with my bank to see what happens there.
Or I can impotently shout in the wind on a Medium post, vow to never do business with PayPal or eBay again, and remind everyone I know to avoid both companies.
So the bottom line is this: Avoid PayPal. Avoid eBay. Neither company gives a damn about their customers, especially when things go wrong.