PHASE 2: next 20 years

The price will move similarly to phase 1 but will start pricing-in future inflation as the market realizes the moderate inflation is not going away.
This will result in pricing Bitcoin in multiples of inflation just like we currently have PE multiples for pricing companies.
Tech companies have PE ratios of 20-25, so it will be normal for Bitcoin to price-in 25 years of expected inflation.
Bitcoin is much more robust than tech companies, it will be expected to be around for far longer than 25 years. Same is true for inflation. So the inflation multiple is not capped at 25 and could go much higher.
There will only ever be around 17 million Bitcoins in circulation accounting for around 4 million that are widely considered to be 'lost'.

Global net worth can be expected to double next 20 years in today's dollars, growing from around $500 trillion today to over $1,000 trillion by 2043.

A 50% global allocation to BTC in 20 years would mean a $30 million price tag per BTC in today's dollars.
From there you could adjust for the past and future inflation via historic inflation and the inflation multiples to get the nominal price tag.

After the nominal price is too high it will be replaced by a different way of pricing Bitcoin, e.g in units of inflation multiples.