Meritline offers two sets of Canon CLI-221–Compatible Inkjet Cartridge 6-Pack with Chip bundled with a Photo Paper 20-Sheet Pack for $21.95. (Select "2 Sets" "under Buy More Save More".) Coupon code "MLCX28YN" cuts it to $12.95. With free shipping, that's $8 under the lowest total price we find for these items purchased separately elsewhere. (For further comparison, we saw a 6-pack with chip for $5.93 in March.) These cartridges fit several Canon PIXMA inkjet printer models, check the product page for compatibility.

Don't want the photo paper? Abacusink via eBay offers the ink cartridges alone for $10.99 with free shipping.