In message m,
writes

we are looking to purchase a monkey puzzle tree and do not want to wait
years and years to enjoy it. Is it best to start with a 1.5m tree or
smaller? How much does it grow per year on average?

About 20cm/year once established. And continues doing that almost
forever.

We appreciate any help/ advice you can offer!

I have grown them from seed. They progress rather more slowly then.

Watch out for and protect from severe cold weather in the first couple
of years. Otherwise they seem to do pretty well in most parts of the UK.

Regards,
--
Martin Brown