I opine that it would be unwise for a pilot to approach Chipmunk ownership with "flying economy" in mind, unless they are comparing it to Spitfire ownership!
It would be a wealthy person indeed that could single-handedly fund running a Chipmunk. However, as I stated earlier because it doesn't go away from base for long it lends itself well to large group ownership with high utilisation, provided the group is well run. That's how I managed to enjoy poling one for well over 30 years on very little outlay. Far less than hiring a club C150, in fact.
And in all those years there was never a 'cash call' on group members - we just paid our modest monthly fee and monthly hours-based flying bill. With a potentially costly bill-generating aeroplane like a Chippy, the group has to be very well run to achieve this. Our's was.