You realize that the Amazon pricing is inflated? The books run cover price ($8.99) at the local grocery store and bookstores... I don't understand why Amazon is inflating the prices. They're charging some people $10+ for each, and then shipping on top of that. I encourage everyone to buy the cheapest way possible and right now unfortunately that's not Amazon. I've asked about this price issue before and got no answer.
There are two paperback versions of all 4 books. The smaller ones are the "mass market paperbacks", which are the ones you see more commonly sold at drug stores and chain stores, etc. Then there are the larger versions called the "trade paperbacks", which are about the same size as most hardcover books. They have larger print and heavier paper than the smaller "mass market paperbacks". Since these Song of Ice and Fire books are all nearly 1,000 pages, I think I would prefer the "trade paperback" versions just to ease the burdon on my eyes. As for the pricing, I can only find "trade paperbacks" for $8.99 or less at Bargain Book websites. Most "trade paperbacks" cost upwards of $10.00 for new books. Most "mass market paperbacks" cost anywhere between $7.99 and $9.99 for new books.
I purchased the "trade paperback" versions from Amazon. They are around the same size as a hardcover book. The paper and the print size is also comparable to a hardcover book. I paid about $10.00 each for them and I am completely satisfied with my purchase. If you can handle the tiny print and flimsy paper in the "mass market paperback" boxed set, the price is very good.