http://www.costco.com/Winix-5500-PlasmaWave%E2%84%A2-Air-Purifier.product.11630632.html

I got this last fall when I had allergies. It works great, can clean a large bedroom. It's nice that you can stand it right against a wall (the inlet air is in front, and outlet air goes out the top), unlike some other models.

I still have the 3 replacement carbon filters.

I'd like to sell it for $100 or best offer.

I live on Stanford campus; don't have a car, so you would need to pick it up.