Staples (link for reference) has InfoGuard 10-Sheet Micro-Cut Document Shredder (NM100P) on sale for $17.50 (price valid in-store at participating locations only) [store locator].

Note, quantities and in-stock availability may vary by location.
For assistance with determining in-stock availability at your local store, click here to use Brickseek Inventory Checker, and enter item # 1541822 along with your zip code