So if the S1 Upgrade path cost $200
How can that possibly be? Where are the $300 worth of parts you would be saving?
Arbitrary numbers I pulled out of my ass to make a point. But, what does it matter? Why does the actual cost of the saved components have to actually be $300? They're valued at whatever BITMAIN decides to value them at and the rest of us just have to deal. Aluminum heatsinks aren't cheap, nor is shipping a huge chunk of metal across the globe in 2-3 days.
Edit: Aside from that you save on the fan + grill, antenna lead, control board, ribbon cables, end brackets, assembly labour, packaging material, hardware, HSC, etc.
Aluminum heatsinks are cheaper than you think. Probably about $5 worth of metal. All those savings you listed are probably less than $50 and $25 to ship.
What exactly will you be doing with the old boards? Will you be throwing them away? That's ~$150 down the drain.