Rotatrims are expensive. I first bought an inexpensive generic rotary cutter from an office supply place, got frustrated with it not working very well, then bought an inexpensive guilloutine-style cutter from an office supply place, got frustrated with IT not working very well, and finally bought a Rotatrim, which has been great. Don't do what I did; just start with a Rotatrim and be done with it, despite the expense.
Based on previous questions on the topic here on this forum, Rotatrim seems to be the high-quality paper cutter that most people here use.
(No idea how it would work on mat board.)
Lisa