Even with a third off, it's still painful to see £200+ being spent on a 1080p monitor. Doe he game professionally and need the crazy fps for financial rewards?I have a Costco membership, got it with a 3rd of the price off so I am happy with the monitor, it fits into his space in his room perfectly.
If this is just gaming for run then it's really a waste of cash.
There's no way whatever space he has will fit a 27" monitor on to let you get into the realms of 1440p 144hz? If that space will never fit a 27" monitor on then there's really no need to spend more than £1500 on the pc and even that's going slightly overboard.