I'm trying to buy the KitchenAid RVSA Slicer Shredder Attachment for Stand Mixers.

QVC has the attachment selling for $44.50
specifics
For perfectly sliced or shredded foods in no time at all, add this rotor slicer/shredder attachment to your KitchenAid stand mixer. Comes with a stain resistant Celcon housing shaft and four numbered chrome-plated steel cones. Designed for use with all KitchenAid household stand mixers.



Ebay has it selling for $42.99
specifics
This attachment performs the cutting and shredding duties your food processor might: select the proper cone, slip it into the plastic housing, and attach all to your stand mixer's hub with a metal shaft. You can shred potatoes, onions, nuts, and chocolate, or slice vegetables for cooking or munching. While it adds versatility to your mixer, the unit is cumbersome to disassemble--more so than KitchenAid's other nifty attachments--and its several parts make it difficult to store. Still, it's easier on your arms than manual slicing and shredding, especially for large quantities, and all parts are dishwasher-safe.