As with many things as far as value goes, the value for these would depend on what a purchaser is willing to pay.
As far as the specific 'trade' dollars (I believe that is what they are called) that you have from Cape Breton, I believe they were printed for a number of consecitive years (I have a couple from 1990), and usually sold at tourist information booths for a dollar or two. Many communitys do this on special occasions, or yearly as a form of promiting tourism and probably for revune. I have seen some 'trade' dollars sell for 5 or 10 dollars, (if never removed from package), but have never seen any sort of catalog or price guide, so there does not appear to me a very big collectors market. I myself have picked up a bunch of these dated either 1977, or 1982, as they are often cheep, and are birth years for myself, and my wife.
hope this helps some, but please note that none of this is guarenteed, just bits and pieces of info I've picked up over the years.