Hi Michael66.
Welcome to our Mattress Forum. 
You are not the first or last to run into analysis by paralysis. I’m happy to do my best to help you through it.
To first address your question regarding the price…(and to quote Phoenix here…)
A different forum subscriber in the Montreal area shared their recent findings/retailers.
Without being familiar with the area, I would recommend reading this article on how to spot a quality retailer over a shady one.
Also, as you mentioned you are both side sleepers…
If you come across any other mattresses that you want us to take a look at, or have additional questions, please let us know!
NikkiTMU