Shipping rates everywhere has gone up over the past year, especially in the last 6 months as more and more people shop online. It's a classic case of supply and demand. Add that to a poor Canadian dollar, and you got high prices.
And 4 - 1.5" wheel spacers weigh more than you think. I ordered 4 of them for a Polaris I owned several years ago. I paid almost $150 back then......and our Canadian dollar was real good then.