Staples.com has CARL RBT-12N a 12" Razor Paper Trimmer with 5 sheet capacity for $2.48. Free store pick-up.
Favorable reviews. I bought it and mine came with two blades (one spare), so it's worth it at this price even for the blades alone. This trimmer costs $9.42 on Amazon.
Saples.com also has CARL Personal Rotary Trimmer with 7 Sheet capacity for $4.89, but it's only 6" and has mixed reviews: