[ian0]

However much you need for your business model to forecast a future you would be happy with.

So if contracting, enough to cover your cost of life, either from the outset or taking into account some forecast of growth due to experience or ability to scale. The more forecasting involved, the more frequently you need to evaluate it.

Sorry, I know not that helpful - but I do mean it with sincerity. It forces you to think of the fundamentals and avoid expensive wrong turns.

[jwilliams]

This is good advice. Start with the level of service you want to provide, then work back from there.