Look at his feedback, both left and recieved.
Feedback of less than 98% positive is not good.
Look at his Detailed Seller Ratings. DSRs below 4.9 are not good.
Send him a question, even one that has been answered in the description. (The cost of shipping to Canada is always a good one.) The tone and promptness of his answer will be telling.
And if you are still uncomfortable, do NOT bid. Another will be along soon. There are 140 milllion listings on eBay every day.