And then, further down in the article, the picture of a whole structure built to block the view of the piece, with a locked door. Satire writing itself!
And if that ruins the character of the building, why is the fence acceptable?
If they're so concerned about cost, why not do what you'd do with any other vandal with a spray paint can...
Immediately paint over it with grey paint to neutralize the "blight", then efficiently do a deeper clean / removal / repair the facade.
Seems like they gave the Banksy very special treatment of fence, guards, etc. and now are paying for the side effects of that.
The BBC says "Banksy works cost public almost £150k" because "The Ministry of Justice (MoJ) says it has spent £50,000 trying to remove paint from the wall of the Grade II-listed building in Carey Street."
Therefore, the title is incorrect. The cost to the public is much more than £150k. The Ministry's damage to this freely-contributed artwork has probably already cost the public a few million £, not just £150k
[0] https://www.dawsonsauctions.co.uk/news-item/how-much-is-an-o...