There is a great $3 coupon on Spot Shot Pet Clean Carpet Stain and Odor Eliminator here. With this coupon, you should be able to find this for free or cheap! :) There are rumors that Target has these priced at $2.99 but prices vary by location so I would just check this out before you make a trip. Sometimes you can even get a price check done over the phone! :)
Thanks to West Michigan Mommy for this update!