I've been scammed a few times when I was new. It's extremely easy to get scammed as a seller. Here are just a couple methods. Buyer pays and after receiving a virtual item - in-game goods, design and programming services or any other intangible then: A. Files Goods not received B. Files an unauthorized dispute. C. Files a chargeback with credit card or bank. D. Buying with a hacked PayPal account. The seller loses these battles 90+% of the time. That's why I wrote my PayPal Virtual FAQ in my signature. Even physical items can easily get scammed.
Paypal is designed to make it easy for buyers to conveniently buy, not to protect sellers. To prevent chargebacks, you basically have to either forget about using PP, or else only take payment as a gift or personal transfer, making it very hard for the buyers to later dispute, because they didn't even transfer the funds as a buying transaction.
You can still open up a chargeback on personal payments. Because there's no way to know if the buyer paid with a credit card, bank transfer or PayPal funds. There are other ways to protect yourself. One way is to get as much personal info as possible from the buyer. Although it's impossible to prevent a buyer from filing a chargeback or PayPal dispute, you can make their life so miserable that they'll think twice about doing it. That's how the verification process works on my site.