Why Isn't Tax Just Added to the Price in Canada?

https://andersonrliu516.wpsuo.com/getting-ready-to-buy-a-house-important-tips-for-first-time-home-buyer-to-prepare-for-purchasing-a-home-in-canada

You're probably wondering about Canada's pre-tax prices. It's mainly because tax rates seriously differ between provinces! Think Alberta's 5% GST versus Ontario's 13% HST