The wish lists are for their classroom libraries. When you buy the book, they give you a sticker to put in the front that says to (and you write the teacher's name) and from (I always put the kids' names).
I forget what I spent at Timmy's book fair, but I know I spent around $25 at Allison's. She got a book and insisted on a cookbook too (she has decided she wants to be a chef when she grows up) and like you, got one for the 2 year old. I know the cookbook was around $15, so I spent $10 on the other two books.