I would aim for something along the lines of this:
Intel Core i3-2100
2x2GB RAM @ 1333Mhz
HD 6850/HD 7770/GTX 550Ti graphics card
Good quality 400-450W PSU (CX-430, XFX Core 450W and EA-430 are good choices)
Case of choice (FD Core 1000, CM Elite 430, Antec 100 are good choices.)
EDIT: I didn't provide links because I don't think Newegg will ship to Croatia, try some local sites for these items.