How to transfer 500k EUR to GBP

Me and my parents are Greek citizens and moved to the UK 11 years ago. My parents sold our house in Greece and received around 500k euros, deposited in their Greek bank. They want to buy a house in the UK with that money (they are both naturalised citizens, I am not).

They are having difficulty with transferring over the money to their UK bank due to different exchange rates, fees etc.

What is the best way to do this? I understand an FX broker like Wise is a good idea, but the commission would be something like 1.5-3%. Revolut has become a UK bank now and it’s possible to send the euros into Revolut, buy a Revolut premium subscription for a month to avoid any fees, and exchange the money into GBP there since they have the best exchange rate. Would something like this work?

Any advice or point to a direction is appreciated!