Sainsburys knocked it down to £117 for the first two weeks of December but put the price back up after.
I would hold out for the 3DS 'lite' , it will come, better battery life and 'built in' second joystick as oppose to the add-on. There is nothing really on the system warranting buying it now. LOZ:OOT and Starfox 64 might be good titles and other than Mario Kart 7 and Mario 3D land there still isn't much i'd get it for.
Don't get me wrong, there are titles coming and a few more that i haven't mentioned but really not worth rushing out for a system over.
Wait for the Vita...toss up the choices and wait for a new iteration of the 3DS