1) Bid on an item from a person that has over 100 positive feedbacks ( check recent activity to see if they are still in good standing, 5 recent negative feedback is a warning to you) and has paypal.

2)Pay by credit card , try to stay away from sending a check or money order.

Its as simple as that. If the seller skips town /cancel from ebay. simply just contact paypal and your credit card company that you didnt recieve the item. you get your money back. No harm no foul. No worries. 

Ebay cant baby sit everyone. So use good judgement. Someone with less than 100 with no paypal selling from Nigeria is someone I will avoid.