No worries. That just means that it's up to you to prioritise.

Here's a "budget" version:

PCPartPicker part list / Price breakdown by merchant

If you think 1440p isn't for you, I'd recommend the U2412M! An alternative would be to go with a supercheap monitor and keep the Palit 980ti in. Or you could go with the 390 and a Freesync monitor. All of these choices should be within the budget! That being said, I'd say that it'd be best to lock your GPU in. I.e., you either buy the 390 and stick to it, or you go with a 980ti. Buying a 330 Euro GPU just to update a few short months later doesn't really make much sense as you'd lose money (unless you get lucky), and especially for 1080p, something like the 390 will be enough. For 1440p, something stronger would be nice tho. So, ya. Choices!