This was exactly what I needed. Just some extra book shelves to line my hallway. I bought two of these. They were on sale on Amazon for $35.99. I didn't want to spend a lot and this was just about right. For the price, it's very good quality and looks nice.
They're easy to put together. The instructions are very clear. It lists a few tools you need, but it comes with an allen wrench and a screwdriver and that's really all you need. You can push the footpads in with your thumb, but a hammer might actually be handy for that. It showed a drill as well, but I didn't have any need for that. I put each together, casually, in about 20 to 30 minutes, taking my time. It's a very simple design.
The inner shelves (2 of them) can be moved up or down a bit using the pegs to vary the shelf height. On mine, I have the lower area at the maximum shelf height and could just barely fit a standard college textbook in.
I'm very happy with these. I've included an image of two of them, side by side.