If Apple would just remove the ridiculous iPhone they grafted into the Studio Display it wouldn't cost so damn much.
I expect the actual Bill of Materials of the A-series SoC and RAM is measured in the tens of dollars. So maybe Apple would knock $100 off.
Does TB4 have the bandwidth for 5k or 6k ProMotion?
There is conflicting information on this, but it sounds like 5K, at least, can be done at 120Hz with 8-bit color depth using Display Stream Compression (DSC).