Guild Wars 2

Hello so i was going to buy Guild Wars: Ghosts of Ascalon so it sent me to Amazon, but which one should i get? Paperback or Mass Market Paperback? why is Paperback cheaper than the Mass Market Paperback?

I just looked at the Amazon page. It looks like the “paper back” option is for used books from resellers and the “Mass Market” is for a new, unused book direct from Amazon. If you have Amazon Prime you get free 2 day shipping with the Mass Market purchase.

Screen caps included.