Firstly, it won't be $500. It just won't
That aside, I don't think Microsoft and Sony are going for the same thing with Pro and Scorpio. My guess is, Sony is using the Pro as a holdover until they can ready up the PS5, with the Pro being more than capable enough for most people to satisfy them. I suspect Microsoft wants Scorpio to be the "base model" gateway console into their ecosystem for close to a decade.
As an example, let's take OnQ's FP32/16 theory and apply it to Scorprio as we currently know it. If it's a 6TF FP32 console, then we can assume (not know) that it would be capable of 12TF FP16 performance. In this instance, it should allow Scorprio to continue to play newer games well into the future even if it means reduced resolutions and performance. It allows Microsoft to continue to drive the cost of Scorprio down over the years and continue to sell it as a cheap option to enter the Xbox ecosystem before deciding to later upgrade to the newer system. Much like Apple kept the iPad 2 around even after the 3 and 4 were done.