And I'm sure Steely, the Bathurst council will be only too happy to have a light show, [billboard if you will] on the mountain promoting the Opera, provided the Arty/crafty crowd will pay for the privilege, something they don't much like doing.

Foxy said "here's the worth of the Sydney Opera House"

Answer- What Foxy is referring to here is perhaps contentious on a number of levels. For me the most important thing is how Australian's feel about the Opera House. But see below for various views on "Value".

"Intangible Value" see

http://www.routledge.com/Measuring-Intangible-Values-Rethinking-How-to-Evaluate-Socially-Beneficial/Harder-Burford/p/book/9781138079588

"Brand Value" (considered by some a form of Intangible Value) see

https://www.thebalancesmb.com/how-to-calculate-your-brand-s-value-2295186

A Summary of Brand Valuation

There are various ways to approach the valuation of a brand, and many of them are debatable. The concept of value often can be a difficult concept to understand. This is because value means different things to different people, so it’s not an objective concept. Valuation is determined by the use of the brand. Popular valuation methods and approaches include:
Cost-Based Brand Valuation / Market-Based Brand Valuation / Income-Approach Brand Valuation

runner,

Incest can vary from gross to absolutely nobodies business, even laughable, but not necessarily to the participants.

//I have no interest is opera or horse racing, but I do find it telling just which bunch are bleating the loudest.//

Yeah, but can you imagine how much of a stink the horse people would kick up if Gladys threw her weight around and ordered them to advertise upcoming events at the Opera House on the jockey's silks? They'd throw a massive tantrum.

I'd much rather see the day's racing with Lucia di Lammermoor's operatic triumph as the sound-track.