thank you for correcting so these cables wont cost me over 30 $ right?
Depends on where you buy them. If you go to Radioshack you should be able to get decent ones for a total of just under $30. While you're there, get a couple of these:
stereo RCA->RCA cables should be easy to find in someone's junk drawer, and put together with those adapters, you'll be set to plug into either a DI box OR a DJ mixer.