Average Charge for Service Agreement

I am a systems engineer in the SW. I am in the process of entering into a service agreement with two of my corporate clients, the goal being: Keeping the network safe, running smoothly and secure. Whatever it takes to meet the goal, excluding hardware and software purchases. I have collected SOME pricing information from several firms around the country, but was interested in gathering more data, so I don't shoot myself in the foot or overprice the proposal. Any and all information you are willing to share would be appreciated.

Make an extraordinary day!

mnathan