I'm certainly no expert but I wouldn't concentrate on whether its curved or not as a factor into the value for money discussion?
Most tech commentators seem non-plussed about whether there is any advantage at all about the 'cinematic' curve and whilst can be attractive is certainly less convenient for wall mounting or finding matching soundbars etc.
If you really want a curved 4k TV of that size then it probably is good value but usually for a reason i.e. the tech in the screen isn't the same as with a £1000+ screen.
I would just do the rounds of all the usual tech websites What Hi-Fi, Trusted Reviews, AV Forums, HDTV test, Techradar, Home Cinema Choice and come up a short list of what is in your budget.
Then go and seem them in the flesh which is the most important thing.
Good Luck.