I clobbed a quick build together in the PCPartPicker Germany:
CPU: Intel Core i5-4570 3.2GHz Quad-Core Processor (€168.89 @ Amazon Deutschland)
CPU Cooler: Corsair H80i 77.0 CFM Liquid CPU Cooler (€84.90 @ Caseking)
Motherboard: ASRock H81M-ITX Mini ITX LGA1150 Motherboard (€60.09 @ Amazon Deutschland)
Memory: Corsair Vengeance LP 8GB (1 x 8GB) DDR3-1600 Memory (€52.90 @ Amazon Deutschland)
Storage: Crucial M500 120GB 2.5" Solid State Disk (€56.30 @ Amazon Deutschland)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive (€51.90 @ Caseking)
Video Card: XFX Radeon R9 280X 3GB Black Edition Double Dissipation Video Card (€269.00 @ Caseking)
Case: Cooler Master Elite 120 Advanced (Black) Mini ITX Tower Case (€45.32 @ Amazon Deutschland)
Power Supply: be quiet! 680W 80+ Gold Certified Semi-Modular ATX Power Supply (€131.22 @ Hardwareversand)
Total: €920.52
This does not include Windows, but it is enough under 1000€ that you can buy one yourself.
I don't know how the prices are in Slovakia, but I think if anything the prices should be lower there
Edit: This also gives you enough headroom for decent overclocking.
Regards,
mentando