Personally, I would not buy a die cutter just for cutting 2.5" squares since I enjoy using the June Tailor Shape Cut mat for cutting strips, and strips can be subcut with the mat into squares. There are some Youtube videos that demonstrate how to do this.
Prism99 said the above and I agree with her. Only I don't always use my shape cut. cutting 2.5 " strips and then subcutting is fast and fun. However, I'm notmuch into handling 2.5 " squares. I just sew the strips together and then subcut. That way the small stuff has already become the big stuff. froggyintexas