Hi Linda. As others have noted, there are many factors involved in deciding how much to charge or expect for these services. In addition to what others have cited, I would look closely at what the duties of the position are, how many people you will be coordinating, and any ‘off-the-clock’ time that you are expected to put in. Factor all of these things in and then take a look at what the people you’d be coordinating makes. I would expect as the coordinator you should be making at least a bit more than they do.
I hope that this helps.