I would get a better monitor before anything else. You can always run lower resolution until you get more cash saved up to build a better pc. Honestly a 1920x1080 display can be had for very cheap now days like under $100. 2560x1440 start around 200.00. I bet you could find a good used one on Craigslist (or similar in Denmark) for like $150.00. That will give you a lot of room to grow the PC.
Common stupidity done by people, buy massive cheap monitor with gigantic resolution and then nothing can properly keep up with it. Also running non-native reoslution on LCD is a very bad idea because image will be crap. Really crap. Stick with the 1280x1024. I had it till half a year ago and it was fine. I just got bored of it and wanted the 144Hz one (which I have now). Great thing with such resolution is that you can run ANYTHING at Ultra settings even on weaker graphic cards. And unless you're really sensitive to screen size, it'll still be perfectly fine.