Hmmm...........
Not certain I understand your rationale on this. Everyone wants to sell high and buy low, which in most real estate market is not possible unless you plan to move from the GTA to an area with especially depressed values.
You might want to look at it from a gap perspective. By way of example, picking numbers out of the air, in a good market you might sell your house for $1.3M to buy another priced at $1.7M. Forget about fees and closing costs to make the calculation simpler. The gap here is $400K. In a bad market let's assume everything in down by 30%. You can now sell your house for just $910K ($1.3M x .7), but the purchase price of the other property is now reduced to $1.19M (1.7M x .7). The gap here is $280K, not the $400K you need when the market is higher. The original gap of $400K is now $280K ($400K x .7)
If you're selling and buying in the same market it might actually cost you less (the gap) to sell low and then buy low.