Hi Branti,
While $800 off a $2000 mattress set (queen) seems like good value (or at least it puts the tempurpedic in the range of other options of equal quality) I would still look at a few things before I went in this direction.
Have you slept on a memory foam mattress before for more than a night or two? Are you comfortable the tradeoffs involved with choosing a memory foam mattress over other options and materials? When you test this mattress … does it give you the pressure relief you need and the spinal alignment that is important? Do you tend to sleep hot on some memory foams?
In post #2 in the “Victoria” thread here, there are three outlets listed (including the 2 you mentioned) which I believe provide the best value in and around Nanaimo. I would certainly compare the mattresses they are offering with the Advantage and then make your choices based on which ones give you the best pressure relief, the best alignment, and are closest to your preferences of how a mattress should “feel” (less or more lively, ease of movement, breathability and heat etc). The Aerus foam at The Foam Guy is very breathable and among the “coolest” of all memory foams.
At the price of the Advantage … I would certainly include it in the running … but it still may not be the best choice in terms of what suits you best even though the value is much better than normal. On a personal level it wouldn’t be my first choice but that has more to do with my own preferences and the types of layering I would choose to “compensate” for some of the weaknesses of memory foam if I were to include memory foam in a mattress.
The good news is that you have 4 choices for good value when most of the people in Nanaimo would only have 3 
Phoenix