We bought a few of these sets a couple of months ago. They're a little flimsy but if you have an older-ish child, that shouldn't be much of a problem. You can't just jam these together. It takes a little finesse. If you break/bend one though, you've got a lot of replacements.
Each set is big enough to make a little igloo/castle/blob big enough for 2-ish small children. We bought one for each of the nieces/nephews so that when they get together, they can make a mega fort.
This + ingenuity + a sheet = hours of fun.