Right guys, I've seen too many people saying they are being scammed by sellers on PayPal after being asked to send the payment as a gift.....
here's what you should do instead
when PayPal asks you whether the payment is for goods/services or as a gift, click the gift field and the fee you have to pay will pop up in brackets usually
this is the fee the seller would have to pay if you clicked for goods/services
so.... note how much the fee was click back on goods/services and add the fee to your payment
this means if anything does go tits up you can get your money back and also keeps genuine sellers happy
EDIT: As a lot of people are using the mobile version of PayPal now I thought I'd edit this as the above doesn't work when using the PayPal app, So here's your alternative solution
PayPal fee calculator
http://paypalfeecalculator.paymentprocessing.cc/