In the U.S., the base price (excluding sales tax) of a 14" MBP M3 is $1,599. The base price (excluding sales tax) of a 14" MBP M3 Pro is $1,999. That's only a $400 difference, not a $900 difference.
In Sweden, the base price (excluding VAT) of a 14" MBP M3 is 19,121 kr or around $1,711 USD. The base price (excluding VAT) of a 14” MBP M3 Pro is 23,921 kr or around $2,141 USD. A difference of $430 USD.
I'm guessing art of the difference is to cover currency fluctuations and the rest to cover any additional warranty requirements in Sweden. I am not familiar with their laws but if it is the same as the EU mandate Apple can simply add teh estimated costs of warranty repairs to the base price to cover the longer period.