I've found metal tips don't work well on the KJW mags.
Try this adapter:
More in stock later this week.
C02 Mags arriving Tuesday:
Here are some available a bit closer to you:
The reason everything is more expensive in Canada is because the market is small here. The more you buy from Canadian retailers, the better we all do, and the more the sport will grow. When you buy from the USA you have to pay for shipping, brokerage, and taxes just like you would here. You just pay the taxes when the item arrives in country. Then you also have to deal with waiting for customs to possible inspect the package.