In Nidelven IT our main product is our time. That is, we sell our time at a rate of 600-1400 NOK (82-192 EUR, 108-250 USD) per hour. The lowest rate is for content management and other simple work. The median rate is for regular consulting work planned some time in advance or requested in a period we don't have a lot of other things on our schedule, and the maximum rate is for urgent and/or stressful work (such as fixing a big production site that is live).
That's it really it doesn't get much simpler than that. :)