Help! The Lightning Thief by Rick Riordan

I hate doing things like this, it's difficult for me to ask people for help like this because I always feel quite guilty. However, I have recently decided what I would like to teach with my seventh grade reading students for the rest of the year, and it requires me to ask for some help. Last year I covered Mythology with my students the last six week and they loved it; and so I have decided to do this again. However, in addition to talking about Mythology, this year I would really like to read the first book in the Percy Jackson series, The Lightning Thief, as a class.

Here's the part where I need help. I REALLY want to have a class set of the books so that students can read as well, not just me. This means I need a total of 30 copies of the book...which is a lot, especially if I have to buy them all myself. So what I'm asking for are possible donations. If you have an old copy of the book you're willing to send for my class to use, knowing they will probably become well loved and not returned. I don't want anyone to give up nice, new copies or anything, just any you're willing to donate. Any help would be fantastic!!