Sunderland store of CeX has Black Ops for both the 360 and PS3 for £20 IF you go in and pay by cash only. I'm not certain how long this deal is on for but I'd imagine not for long.
If people could check their local CeX to see if it's nationwide would be great. I probably should of taken a pic of the advert so apologies for no "proof". However I'm sure if there are people here who live in Sunderland can back it up if they check.
I will add further info as and when we get it. I will also popping back into town later so will take a detour and take a pic of the ad.
So far this appears to be a Sunderland store deal ONLY.