If you think consortium membership is costly then you’ll be in for a real shock if you set up for yourself (you can join a consortium for well under £300 per year). If you are presenting for another training provider then you will use their material (all the modules need registering with JAUPT). Nothing stops you from copying other peoples modules when you present them.
As a matter of personal opinion I think you are better off with a teaching qualification such as PTTLS rather than some non recognised in house trainer course.