depends what you select for the reason you returning the product, If you choose to return it because you don't like it for whatever reason then you pay for the return.
but if you select that the item is defective or doesn't work properly then Amazon pays for the return label, all you have to do is print the label and wait for UPS to come and pick it up two days later.
Another thing to add onto that: Amazon has a little "loophole" in their policy to screw you out of replacements on monitors, if the reason you select for defects are "close enough". For instance, they were going to deny me the third one down for that very reason, because both of the VP2770's I got before that one had pixel issues. I had to literally go down and explain to them that the reasons were not the same. They don't discriminate between position of pixel problems or anything, they just go "well, since your reason for replacing this one is close enough to the last one, you should just return this product because it's not right for you."
So no, the Amazon return policy is not as friendly as everyone would like for you to think it is. It is in general good, but for things like these 1440p monitors where you can get several bad rolls in a row, the best option is Microcenter. I don't think I've ever had an issue with them taking a return back from me. On the other hand, you have to go drive there, and their stock of anything high end can be... bad.