I can't speak for what it is at Mainline carriers, but at the regionals in two words, not much. I think they start in the low to mid 20s at the regional level.
I will say that they don't get paid nearly enough for the job that they do. Basically, they are the ones that have to reroute crews, and make sure that every flight has a qualified crew on it, which at my carrier, means 500 flights a day, and you have 800 pilots, and 400 flight attendants on payroll. Not only that, plus you have to deal with angry pilots, and mx issues, and ferry flights, and getting inpromptu hotels if necessary, and they have to sort through all the trip trade requests and sick calls, it is the most thankless job at the airlines. And not only that, you have to work odd hours, and get paid very little for it. Its a tough job, and at my company it has a very high turnover rate. I don't even know most of the people over there anymore, and I work in the same room as they do. Its really sad, and if it continues and you have nobody experienced left, which may well be the case at Mesa from what I have heard, you are really talking about a disaster waiting to happen.