That Ontario Battery
site has a link for their RV catalog, which puts you in the Go-RV
site. If you follow a dealer's link (such as one from Ontario Battery) you get their pricing; as an alternative you can pick your province (or state), you get a list of dealers who carry this line, which likely means a local source if you don't want to order on-line (the prices are for the dealer you choose).
By the way, this Go-RV's full catalog, with solar
panels and everything else under the sun.
Whatever your source, be sitting down when you check the price of any significant size of panel: a really rough guide is Cdn$10 per watt.