Every TPE split I do, I receive the aircraft minus 700 to 900 kg's of fuel. No maintenance done, no checks done. There is no F.O.P. budget for ground power unit's but A.P.U is part of the operating budget. GPU's will have to come from a maintenance budget. Not only will a ground power unit save fuel and noise pollution, but it can be rented out when not required by C.X.
But then pilot's don't have the big picture on business unit budgets.