[XDJ-XZ] vs [AZ] vs [2x CDJs and a DJM900NXS2]???

Which one will prepare me for any club setup?? I don’t have the budget for a full CDJ and DJM setup, but I’m seeing people selling their XDJXZ. I just wanna make sure I’m making the proper choice for my investment. (Modest income household, college students paying bills)

But help me out here, I need the best bang for buck! Without sacrificing too much.