Canon has this sale on again where you buy two CLI-42 ink cartridges for the Pro-100 printer and you get 50 sheets of 13x19" Semi Gloss SG-201 photo paper free, plus you'll get free shipping. So, if you buy a complete set of eight ink cartridges, two at a time in four separate transactions, you'll get 200 sheets of the semi gloss paper free. Don't know how long this deal will last. The pack of 50 sheets of paper itself sells for about $55. Here's the link -- PIXMA PRO-100 Inks | Canon Online Store

Canon has a similar deal on inks for the Pro-10, but you'll have to buy three cartridges to qualify for the free paper.