Prophead
The only way to get the cost down is to keep the aircraft in the air as much as you can after all in you do one hour a day the fixed costs amount to 1 landing @ £10 and one nights parking @ £12 giving a total of £22 to add to the hourly rate.
If you fly the aircraft for three hours a day the fixed cost is the same but the cost added to the hourly rate is £7.33p.
Also if you fly for three hours it will give you the chance to get the mixture set to optimum for a greater proprtion of the flight, optimum setting saves about 20% on the fuel flow over rich mixture.
Economic hours building requires high use of the aircraft over a short time span, that is why I can provide aircraft in the UK at prices that match the USA dispite the extra tax burden in Europe.