TN
In my experience:
1. In the past HQAC was seen as a backwater and very little money was spent there. You only had to go there when it was at Newton to see that. Since the move to Cranwell IMHO that has changed.
2. Quite a bit of money has been pumped into HQAC and ACCGS (2FTS) in recent years both on kit and on facilities. How well they have been used is another question but not a lot of money is spent at either Region or Squadron level overall, and staffing costs once you move below Region level are minimal.
3. When the RAF was large and fighting the cold war no-one wanted to know about Air Cadets (lets face it, a posting to a backwater location at Newton working with RAFRO, RAF VR(T) and kids in discarded battledress or working with Aircraft over 50 years old and second rate MT on a disused WW2 airfield is not going to further your career too much). Suddenly with no cold war to fight and a much reduced RAF, the Air Cadet Organisation was seen as somewhere you could continue your career and ultimately even engineer yourself a second one for when you retired. Lots of people took an interest in it and Government Policy suddenly swung to 'looking after the Youth' - this meant funding magically became available for the 'organisation' - very little trickled down to lower levels I can assure you.
4. So in answer to your question I would say at lower levels the ACO provides tremendous value for money in terms of both the public face of the RAF and as a recruiting tool. At higher levels I would say it's an expensive edifice run by people who think they are running a corporation like ICI rather than a national Youth organization with an aviation slant.
Sad, but true................
Arc