Aluminum heatsinks are cheaper than you think. Probably about $5 worth of metal.
Find me those heatsinks for $5 with a MOQ of 2.
Why? Bitmain buys heatsinks by the thousands.
All those savings you listed are probably less than $50 and $25 to ship.
So you're just talking out of your ass then? May I take a moment to repeat what I said...
You are imagining that there will be ~$300 in savings which simply cannot be the case. There cannot even be half that amount considering bitmain sold complete S1s for $200 and chips make up something like 50% of the production cost.
Which components do you think are so expensive?
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.
What exactly will you be doing with the old boards? Will you be throwing them away? That's ~$150 down the drain.
Sell them for 25$ and let someone else worry about it. Hell, if I'm so inclined maybe I'll have some of their control boards made up and sell those too.
So you are going do remove the heatsink/fan/thermalpaste/case/cables/controlboard and sell your asic boards to someone who will then have to add their own heatsink/fan/thermalpaste/case/cables/controlboard at a greater cost than bitmain would pay?
Do you see now why this does not make sense?