The point I was trying to make - apologies for not making it clearer - is that from the point of view of the ETH{insert favorite fiat currency here} market figuring out what the how the supply will behave is hard, and therefore hard to price.
Maybe, but I didn't have that formula handy and found it with a couple minutes of googling, so it's not that hard.
In any case, by the time the full transition to PoS is complete, one thing that will be easy for the market to know is that issuance will be substantially lower than BTC, and possibly negative depending on transaction fees.
For PoS, issuance is a formula depending on the amount staked. How that works out: https://docs.ethhub.io/ethereum-roadmap/ethereum-2.0/eth-2.0...
If you want to dig into the actual formula, it's explained here: https://benjaminion.xyz/eth2-annotated-spec/phase0/beacon-ch...
Until PoW migrates to PoS, probably in about a year, they'll operate in parallel and we'll have both rewards added together.
A final factor is an upcoming change to the way transaction fees work, which will burn most of the fees instead of awarding them to validators. That will reduce net issuance further, possibly even taking it negative.