Something's wrong with this picture.
Why would any LHBS 'order grains pre-crushed from their supplier,' instead of ordering whole grains and crushing them as people buy them - thereby making staleness almost a non-issue? WTF? They can't afford a Barley Crusher???
Personally, I never buy my grains crushed anyway. Partly that's because I like my own crush better than what I've gotten from even my favorite LHBS, and partly because I brew in the desert, and figure whole grains survive high temp's a lot better than crushed ones do if I don't use them immediately.
Interestingly enough, I know small breweries that don't crush their grain but rather order it pre-crushed. [I know this isn't what you are saying, just trying to provide a complete picture of the options for those who might not know.] They do so because they don't want the "hassle" of crushing a BUNCH of grain, and because they use the grain quickly after it is delivered.
Myself, I invested early in
a) A Barley crusher which I motorized, and
b) Buying grains by the sack and keeping them in sealed airtight containers prior to use. For grains I will frequently use, I keep them in food grade containers with gamma seal lids. For grains that I need to keep over an extended time, I either seal them (for specialty grains) in 1 or 2# increments, or use mylar with oxygen absorbers for even longer term storage, especially for larger amounts (I typically break up sacks into a couple 5 or 6 gallon buckets with the contents sealed in mylar.)
With bulk buys of grain and hops and washing yeast my typical 5 gallon batch of a decent IPA recipe is under $20.
To the op: Given that Canadian Malting's
http://canadamalting.com/our-locations2-row is sold in the USA in the $35 or so range (and I have a BUNCH in my house), it's hard to believe there isn't someplace in Canada where you can order it for a reasonable price.
ETA: OP, just found this in a google search, perhaps it will help you:
http://www.bulten.ca/homebrewing/suppliers-in-canada