Here is an updated list of the prices for Pazzles supplies on Walmart.com and Amazon.com. Keep in mind that you don't have to pay shipping cost with Walmart if you use Site to Store. Prices include shipping to my area in GA.
Walmart Amazon Date
Mats (12x12) 14.88 18.58 July 11, 2012
Blades 13.14 15.48 July 11, 2012
Machine 477.19 487.49 July 11, 2012
Pen Tool 23.96 28.98 July 11, 2012
So, with shipping, Amazon is more expensive than Walmart, at least for July 2012. Trust me, the prices change frequently with these two vendors.
Tip: I bought a set of Cricut 12x24 original mats from Amazon and paid less than $19 with shipping. I cut both mats in half and now I have 4 12x12 mats. I'll let you do the math on that one.