I'm open to correction on this but I'm almost certain that €2k is a minimum balance and, provided you meet this minimum balance, interest is applied to the entire balance (including the first €2k) up to €2m (ie it's not a tiered rate).
I agree that the way the "Best Buys" section is written could be interpreted to mean that interest is only applied by NUK on the balance in excess of €2k but I don't think that is correct.
Yeah. The rate is not tiered. €2,000 is the minimum initial lodgement rather than the start of a tier. I have edited the best buys to make this clear. Thanks for pointing this out.