I have found some of the NO FRILLS have a restaurant food service type section and have
huge sizes of rice, flour, baking powder, baking soda, salt, jello, crackers , spices, tang ,
bacon bits, rolled oats , sugar, condiments, and loads of stuff.
They also have #10 size of canned stuff ( not the dehyrated or freeze dried ) .

Find out where in your local area Restaurants shop.

grain process enterprises in scarborough has been listed on many sites. However, I just asked for a quote on some things like rice, split peas etc. and their prices are more expensive than going to no frills

Wholesale Club has large commercial bags of oats but when priced out it was cheaper to wait for the small family sized bags of oats to be on sale in the grocery store and then stock up and repackage if necessary (some brands now come in those brittle cello type bags).
Sugar is cheaper to wait for grocery store loss leader prices unless Costco has it in at a good price/kg.
Flour I buy at Costco or when it's on loss leader prices for the biggest grocery store size (this is usually Xmas, Easter and Thanksgiving sales).
You can get big boxes of baking soda at Wholesale Club and Costco also has good prices on big canisters of cocoa powder and baking powder.
Rice I wait and watch for Chinese New Year or other Asian festival sales and buy the BIG bags at very good prices, sometimes up to half price and you can get different varieties at that time too (Jasmine, long grain, short grain, Calrose).
Beans and split peas I buy at stores that cater to the Indian community or Wholesale club...they have MASSIVE bags of beans and split peas at reasonable prices compared to BulkBarn and grocery stores.
If you don't have to have brand name "Jello" the brand Dollarama carries is good quality and cheap.