The Westin Dublin has gone up to a Cat 6 which means it's available from 20,000 a night, 25,000 in high season. I took a look at about 20 random dates over the next year and average prices were often North of 400EUR, so it's not unreasonable. That said, the rates do seem unusually high - I stayed there for a night a couple of weeks ago for 220EUR.

Dublin is economically booming at the moment and is a completely different place to a decade ago after the crash, so it's not a surprise to see the city's primary business hotel has been able to increase its rates by that much.