Yah was looking and found it, it's like 15$ for shipping which would be more expensive than getting it at Gamestop.ca.
I found on Amazon.ca it is 23$ used, is amazon a good site for buying?
Quite often, yes. Amazon is some what like eBay where different sellers can list a product, and often times Amazon will sell the item themselves. I use them to when looking for games I can't find in stores anymore and have had nothing but good experiences with them (good pricing, selection, and quick shipping/delivery times).
And looking at Just Cause 2 there is one new from Amazon for $18.75, and 2 others that would come to about $20.00 with the shipping. (Do not buy PC games used, ever. You are almost guaranteed to have had the CD key used, thus giving you an expensive coaster.)
Edit: Amazon does not accept Paypal payments, sadly.
Double edit: I just realized you could have very well been talking about a console version of JC2, I assumed PC. That would be my mistake.