It had always been something that I have been interested in (importing firearms) I would like to one day own my own range and shop. I think saskatchewan has a high demand for a shop that offers more restricted firearms. Its always good to have more shops offering surplus weapons they are always hot sellers. Especially at gun shows
Don't let anything deter you, there will be an increased demand for restricted all over Canada as the sport continues to grow. But military surplus is non-restricted btw

Unless you mean rare or uncommon in place of restricted, referring to them as hot sellers at gun shows
Also if you want to run a shop, you want to be a reseller / dealer of firearms, not the importer / distributor / wholesaler. As a small shop you won't have the capital to purchase thousands of rifles at once and millions of rounds of ammunition like the above posted noted. You the guy that will buy 5-25 pieces at a time and sell them through your channels. Then replenish with another 5-25 and continue on that way.
Basically when you look at the current firearms market in Canada, there are a few very big importers/distributors....Marstar being the largest, they probably supply 80-95% of the surplus firearms to the Canadian Market, as they have the resources from many years in the business to send folks around the world shopping for these items and have the capital behind them. Most of modern stuff especially American products (glock, ruger, etc) most stores import there own small quantity stuff directly from the factory as its much easier then coordinating the import of stockpiled surplus.
So thats kind of where you want to start. You buy/import direct for the common brands and modern stuff, then you create a dealer/reseller relationship with a larger distributor like Marstar to move the surplus stuff around your area. When you big enough, you can start importing small amounts of surplus if you can seek it out