I agree, Murrayfield is a good idea. No transition to training area, however, for Comm training it is more of a trek to CTA than JT, so weigh up the 'VDO time to get there vs savings on JAH charges' etc..
Instructor Rating will run you between $13-16k at Jandakot, not sure about Bunbury though, would be a ballpark figure. Can't really give you a number on cost of Comm training. Not cheap tho..
Good luck with whatever you decide to do