Once you get both of them figured out, it will be like walking
I have used both eBay and PayPal for a number of years now and have had MINIMAL problems with either of them... particularly when you are the buyer.
The only issue I have come across was when a buyer initiated a dispute (it was something minimal and was easily resolved). During these cases PayPal pulls the amount of the transaction out of your PayPal account, even if it means giving you a negative PayPal balance. Once that happens you can't use your PayPal account unless you deposit that amount back into your account... which really means you are out the item you likely sold and the money, until the dispute is solved. In my case, I was selling new items which I was purchasing, not just stuff I had laying around... which meant that I had already paid my vendor for said item(s) and would have had to pay again to PayPal to use my account until the issue was resolved... meaning extra out of pocket expenses to continue business using PayPal.... what a headache!