£200 is a fine price for the Dell U2711. It's an old monitor by now, but I imagine it still holds up well. As said above, Dell make good monitors and the UltraSharp models have been consistently impressive. The monitor was £800 or so when it came out and IPS technology as far as I know hasn't changed that much since it was introduced so it should still be good. If you don't need modern features like 120Hz refresh rate, adaptive sync, or very low input lag, it's probably going to be a nice monitor.