Purchase Two Pre-owned Products and Get One Pre-owned Product of Equal or Lesser Price Free
Limit 1 coupon per customer. Coupon must be surrendered upon use. Free item must be of equal or lesser value. Hardware not eligible as free item. Not valid with any other offer. Selection may vary by store. While supplies last. No substitutions will be made. Valid on in-store and in-stock items only. Not redeemable for cash. Offer valid through 8/31/11.
Just checked my active offers section on my powerup rewards account and saw this as an active offer. You will need to print the coupon out, and it says "products" so technically it should work on accessories as well.