The answer was "Learn Computerese"

If you got my clue, you would have realized the alt in alterior was a little bit bigger than the rest.
(Also, there was a subtle hint in the puzzle itself, about computer geeks)

If you hold down the alt button, and enter in each number set separately,
i.e. [alt] + 156 = £ (let go of alt after each set of numbers)

I have very good news. Des has told me that I have some prizes to award.
According to him, there are 3 copies of "It's a mad, mad, mad, mad world" for me to distribute to winners of my puzzles.

:P toldja there was incentive

Next Puzzle should be up as soon as I'm bored, prolly later today or tomorrow.