I also don't get it Peter. We paid 500k for our 5 bed house near Felixstowein 2018. 12 months later the one next door which is identical but a far saller garden went for 565k. Now it is worth c 700 to 750k. This despite roughly 4,000 new houses being built in the immediate area.
The cheapest ones they build are generally 3 bed terraces at 250k plus. Suffolk folk don't have huge salaries.