Food prices in Canada relative to USA are higher because of the cold weather. Cold weather results in lower productivity in agriculture, which means high cost of production for the farmer. Also the government puts heavy duties on food imports to protect local farmer, so no cheap imported food either. So price of food is high.
Interest doesn't have much to do here, rates in canada and usa are similar. gold standard has nothing to do with price either.
the main thing is supply vs demand and market structure. in canada u have very little (compared to usa) competition, and many monopolies which means they charge higher prices, plus due to the fact that they have every other thing heavily subsidized (education/healthcare etc...) they have higher taxes to make the budget balance. this results in everyone paying the price for cheaper healthcare/education of everyone. higher taxes means they set the minimum wage higher to make sure people are happy, this results in higher production costs (cuz of higher labor cost), raising prices.
pakistan also faces a problem with subsidies. we have subsidized power, meaning that the government buys electricity from suppliers for "X" and sells it to public for a price "X-Y", where "Y" is the subsidy which is again coming from our pockets through taxes. End result is that every major big time company/group in the past decade or 2 has setup its own power company where they imported a used $hit efficiency oil/gas fired plant and sold electricity for somewhere in rs30s per unit whereas the highest price we were paying was around 15/unit. So basically bad government resulted in total loss of public, huge profit for power company and big bribes for those involved in setting up the deals(senior gov. officials). that is the circular debt problem, the government(s) made deals worth money they couldn't raise through taxes. the new revised power brackets make alot of sense, just raising price without changing brackets would have made no sense. with new brackets, poor people will get cheaper rate compared to the wealthier.
Due to the higher rate for the rich and the fact that they have lot of cash available in bank, they will look at alternatives like solar power. currently, $0.55 (american) gets you one watt rating worth of solar panels. a 1kw panel will make ~3.5kwhr per day avg(for the year). Considering current electricity rate at highest bracket and interest rates, solar power is commercially feasible if we shift all or most of our daytime(solar powered) load to DC power. I think gov should focus on an awareness programme aimed at educating the industry about solar power and encourage them to invest in developing/acquiring DC powered machinery so solar power can be efficiently used.
And then there are some idiots (in pakistan !) who have invested upto 20 lacs in a solar $hit kit that gives a return(at current electricity rates) of less than even 5%/yr because they bought batteries and invertor and other non-sense and I was amazed to find out one of those I read about was an electrical engineer(genius?). Solar power is effective if you use the power when it is produced and in the form it is produced in. simple rule.
^sorry for off the topic solar nonsense..now back to topic 
Another thing that raise prices for canada is the fact that its a smaller market, meaning lesser production, meaning higher cost compared to america which has an economy 7 or 8 times as big. When you double output at a large scale, cost reduces a few percent every time you double. So as canada grows(in population and GDP), prices in general will fall. Plus the big oil reserves of alberta (recently in the news) will speed up the process when more labor is imported and gdp grows even faster.
so yeah, price/cost is not determined by gold standard or interest rate.
it depends on:
-competition
-demand
-supply
-taxes/subsidies
