For me personally, because we are not near a major city like Toronto or Montreal, I find there are a couple of options.
1. Look up Tidd's Honda. It's a Mom & Pop type of dealer in Houlton Maine. Great people to deal with. They will bring in what you need (if they can get it) and call you when it gets there. Drive across the border and pick it up! Even if you have to pay duty, you save by getting US prices and not paying for freight and shipping charges for it to come in from a major city.
2. David Silver Spares (England)...excellent source, great customer service, online tracking, and finally......ships to your door in New Brunswick cheaper than most Canadian or US parts dealers. I got 4 full carb rebuild kits, fork seals, a clutch cable and brake pads. Cost me about $8 cdn for the shipping and only took 6 days.