There is nothing wrong with buying off eBay. Back when the Cdn dollar was good and you didn't need a mountain of paperwork to bring a scope into Canada from the U.S. I bought several high end Leupolds for really good prices. Just be sure to do your due diligence, research the seller and buy from a reputable seller. Use common sense too. If your buying one from China for $250, your probably gonna have a bad experience.
Good Luck.