Would you rather buy something cheaper and pay shipping, or more expensive and free shipping?

Question

Trying to figure out what people like more: 

$10 and $5 shipping, or 

$15 and free shipping... 

Answer 1

$15 and free shipping because of if it needs to be returned. Shipping charges are seldom refunded with a return. If shipping is free, the buyer knows for sure right off the bat that if it needs to be returned, that they'll get their full $15 back, not just $10.