That's not a money issue if I can afford to own and run this plane, then can afford a suitable instructor too. When I first bought this plane in 1995 I had the chance of being trained by a world champion who was also a friend.
I then thought I knew some aerobatics after 8 years in the aeroclub flying a Cap 10. And 2 aerobatic ratings (Basic and advanced).
But I soon realised that I had to start all over from scratch, even the very basic manoeuvers had not being thought correctly. But aerobatics especially advanced aerobatics is a matter of enthusiasts, not club instructors. How many Alan Cassidy's have you got around there, not many I can assure you.
The prospective earnings are meager ( 15 min flight, do your calculations) and you land exhausted and sweaty. To reach an acceptable level likely to enable anyone to teach involves so much investment. Totally uneconomical
The point is that there are no instructors that I know capable of doing a sensible job flying these planes, let alone fly a circuit in one of them. Not that they are incompetent, they do not have the background. Then one cannot rent such machines, only own them. With very few exceptions.
So when you may need some help, better resort to your good connections, mostly competitors and display aerobatic pilots.