Leven Thumps

I have been reading the 4 book series for about the last 2 weeks. I went to Deseret Book and found books 2 and 3 for $1.99 each. They're the hardcover, I couldn't pass it up. I have been wanting to read it for awhile now. I checked out book 1 at the library and read it and number 2 and then before I started number 3 went to the library so I would be able to get number 4 quickly and read it when I was done. I think I read number 3 in 2 days. They are about 300-380 pages. They are fun books that are not really Harry Potteryish, but fun in there own way. I am into them and cannot believe how the characters in the book hardly ever get to rest. It's almost exhausting just thinking about. Tired and hungry, as well as constantly moving, with the what's gonna happen next feeling. I think I will check for #4 at the library today. Does anyone know where I can find #1 and 4 on sale?