How can I choose a relative colour scheme for prices?

Question

A client needs a piece of software where he can see what price he should be using for his products. Ideally you would say that an expensive price should be red. It is, after all, a negative experience. But the big price would be a positive sign for our customer. As it would indicate that he makes more money...

I'm looking for the best way to show this:

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All the possibilities I can come up with have multiple meanings to them and could easily be misunderstood. Arrows pointing up could show a positive increase and dito negative increase. Green color could show positive progression, but how is positive interpretated?

Answer 1

How about using Bold Black for your best price, and gradiate down from there, so regular face grey color for competitors and your last year price is red, and probably keep it beside your new price. That way you differentiate yourself, and keep the focus on your great prices?

Answer 2

If the client requested this comparison in the first place, I would ask them what their interpretation of the data would be. That would dictate which colours, if any, should be used to aid that interpretation. As you say, whether or not the numbers are 'good' or 'bad' depends on the user's point of view. I'm not convinced colour is very useful here though.