Do you mean the Armeg bit for £29.99?
I bought one recently for lifting a couple of bathroom floors and it worked very well. It really got under the tiles to lift them. I haven't tried it yet on walls and I not sure how much damage it might cause - I guess it largely depends on how well the tiles are fixed.
My drill is a 4kg brute so that won't help either

Which drill are you thinking of?
Mark