Craig's List and PayPal are sometimes not the best combination.
For everyone to be protected, (both buyer and seller), the seller should send you an Invoice with the item description or have a web page setup with either a Buy Now or Add to Cart type item button. In order to this, the seller would have to have either a verified PayPal Premier or Business Account. You can then either pay as guest on the PayPal Checkout Screens or pay using your PayPal Account. The item you're buying has to be tangible, something that can be shipped, tracked and insured if applicable.
If any other kind of deal is made, as a buyer you're at risk. For example, you should not simply use the Send Money feature to pay for the purchase. Nor make any arrangements for delivery, i.e., self pick-up or a courier type 3rd party delivery service, etc. Also note that intangible items such as digital goods, event tickets, vehicles and services are no covered for either buyer or seller protection.
Suggest perusing thru the User Agreement for your own benefit. Note, if you're dealing with a not so honest person, they already have read PayPal's Polices.
https://www.paypal.com/us/webapps/mpp/ua/useragreement-full
