Is it worth it? (Stanton T90 USB)

I was looking on ebay and found a pair of Stanton T90's on auction for £30 (~$48), I have never used turntables before and I have been using a numark totalcontrol controller for the past 2 years, what do you guys think?

The auction will end in about an hour.

I also want to use it with my pc using something like serato scratch live but Im on a tight budget, would I need something like that for these turntables as they are usb?