My costs per flying hour based on 900+ hrs per year are around NZ$240.00. This is fuel (70-75 ltrs per hr ) engine and prop replacement / overhaul, insurance, maintanence + a bit for unscheduled stuff. This is not allowing anything for a full paint job and interior at some stage, hangerage or any new avionics that may be needed. Obviously fuel price fluctuations can change this figure quite a bit, at the moment I am paying around NZ$1.90 per litre. Also no finance costs included. Would be pretty close to your figure 185skywagon, taking into account exchange rate and a few things.