All training for licences has to be conducted at an appropriate organisation. For the PPL it is currently known as a Registered Facility but from April 2012 it will have to be an Approved Training Organisation. All higher licences already require an approved Training Organisation so its not quite as simple as buying an aircraft and finding an instructor. To get to ATPL level its going to cost around £40,000 plus; owning your own aircraft is not really going to help beyond the 150-200 hour stage.