it might be cheapest overall to get a usb turntable (eg
http://www.jr.com/JRProductPage.process?Product=4160377); built-in pre-amp so you can skip the mixer. record into computer or straight to mpc.
you could buy a cheap belt-drive turntable, then get a fairly decent cartridge (good sound quality) and a mixer. my only beef with that numark portable turntable (or my vestax handy trax which hasn't been tested yet) would be its sound quality.