Why have a guy per 15 companies. What happens if that person is off sick for a week? or even if that person decides to leave suddenly? Also you manage the budgets yourself for each of the companies? Funny way of doing things! 10-20k should just be for the support contract of 24/7 support, time onsite should be charged per hour extra. 15 companies should be bringing in around 250k a year. Worth having 1 guy per 5 companies to take the load off and being able to work on other projects. Sounds like a risky business model.