This is a never ending cycle of people chasing more and more money. If you're paying them fair market value for the area, then there's little point in giving them a pay rise for asking for a nap because they're tired. Chances are, they're chasing contract gigs because they have their own interests in the work or they just see the dollar signs - I know I do it... but I also know that come 10pm I'm wasted and have to hit the hay to start it all at 6am again the next day.