Not sure if this applies to airsoft, but usually when trades go bad on forums. I'd recommend people to report to the Mods, and
http://trollhunters.com/, at least that's the case with computer-related forums. You can give it a try.
(For future purposes) As much as ASC is a small community, when trading online, always look for references, in this case, he used his ebay as reference (since he has only 1 trade rating on ASC), so I would email that ebay account to confirm it's his. Also, just to make things easier, I would also recommend asking a phone number and call him to confirm, etc.
And not to bash you, LaZeDoUt^, but why would you ask him to ship something when he lives like 10 minutes away from you living in Markham. If anyone preferred paypal over cash, I would feel a lil iffy and pick up the item physically and pay him on the spot with a laptop.
But the GOOD thing is, if he is in Markham, I would ask the Mods for help for an IP, and report this to the police. The police would likely be more involved if it's a local deal since it requires less effort.
Best of luck with it. But definitely report to the mod to see if they can provide information on the matter, and also file a report to the police. We certainly don't need dishonest traders in this community.
EDIT: His ebay account is still active, so I really doubt that's really Gamers' ebay ID.