i've never had any experience with usb turntables, but Numark has one that you can find online for around $130. I have a Numark turntable that i've been very happy with, and the company was very easy to deal with and courteous when i needed some replacement parts (something fell off the shelf above the turntable for some unknown reason...) so if you're looking into a product like this, i'd be comfortable recommending Numark.
CMT-340SE2 Mains & Center, CBM-170SE Surrounds, Rythmik F15, Emotiva XMC-1, Emotiva XPA-5