well I manage only my server :D
but yes the rates include management of server also....check the link I provided, they have different management plans also...
check this page for server manageent plans they have..
http://www.servermatrix.com/managed_services.html
I think for linux server basic plan is more than enough if you know how to use linux...or you can even go for gold plan which is $50 per month and gives 1 hr a month of system admin..i.e. their person can install any software you want..or make changes in the system as you want...
Deep