True costs for a C150 based in South of U.K. over last 12 months:
Insurance £ 1,056.00
Radio Licence £ 20.00
Maintenance £ 3,267.92
Airport Fees £ 3,195.04
Plus fuel, say 21 litres per hour (actual burn usually less), and this covers pretty much all that you need except for the occasional litre of oil between changes.
Don't forget to allow for an engine fund towards the eventual replacement/refurbishment and remember that the airframe will need respraying about every ten years.