I have to say i'm a little surprised at Ian Cutress, to say because AMD are adding 50% more die it would drive costs up 50% to keep the same margins. That's not how it works.
At $20,000 per 12" wafer one 8 core CPU chiplet is costing AMD $28,80, The IO die is much larger but old GloFo 14nm, its probably about $10, so the die material cost for a 5600X / 5800X is about $40, about $70 for a 5950X, with the 3D stacked L3 it comes to about $105.
The die material costs are only a part of the overall costs, you have the PCB, the Heat Spreader and manufacturing costs on top of that, that could bring the 6950X to $150+, the actual cost increase is probably only around 20%, AMD might absorb half of that cost and if they are selling in to the supply chain at $400 it might only cost the a couple of % margins on that product, a few $, they could adsorb the whole cost and it wouldn't make any meaningful difference in the grand scheme of things.