It’s about half the standard Naim pricing for a service, or a repair. Though it does sound more than they were charging for a screen replacement a while ago, which I thought was £150 odd.
fwiw I chose to have my UnitiQute 1 screen replaced as part of a full service and board upgrade last December - that was about £500 all in. I thought that good value considering the parts list and work likely involved.
Given the way of things with shortages and items going out of stock, or unavailable, I’m with feeling_zen here, it might be worth getting the screen done whilst you know you can and asking for a quote for a full service at the same time. Here’s what a new screen looks like brightness wise 
