Well trust me I know how it works;
1. You should always make sure to use long random passwords to your pp/ebay/email account and there will be a zero chance a harm can be done... he can do nothing with your email address/name.
2. Nobody uses the brute force method nowadays on PayPal and it won’t work anyway.. PayPal limits the number of login attempts from the same ip address.
3. The only method you should be afraid of is probably phishing which is not the case here.
They are definitely wasting their time, unless he is one badass hacker, a real hacker will not try to break into the database of pp or ebay, for the simple reason that they are super secure(Most known online payment systems such as pp spends billion of dollars each year in security, to make sure your money is safe).
And even if by some miracle they managed to get their hands on your money, you still have the credit card company insurance...
The most likely scenario that I see here is that these hacked or brand new ebay accounts with "too good to be true" listings are being used for data collection.
You probably don't need to worry about being hacked as a direct result of attempting to buy any of these listings, but you probably should be aware that Someone(tm) nefarious is out there hoovering up info on paypal customers to use later.
What's probably happening is that this information is being collected to cross reference against password lists from cracked sites or breached data from somewhere like Equifax. For example, your paypal email address is probably the same one that you use with your bank and your credit card companies.
Thanks to eBay these people also have your mailing address, and possibly your phone number. That data combined with breached data from someone like Equifax would make it pretty easy for someone to open new accounts in your name too.
Anyway, this is all speculation -- but I'd be extremely wary of making life easier for nefarious data collectors.
tl;dr: I doubt this is about someone trying to brute force your paypal account, whatever it is it's probably scummier.
