“What makes anything worth what it’s worth? Whatever someone’s willing to pay for it. I’ve got one at the end of my road. Has it increased the value of my flat? I’m not sure.”

“Priceless. Any artist is good for attracting people and populating cities.”

“You can’t move it, so it’s priceless I suppose. It’s just cool for everybody to see it.”

Cool to see for free, but there’s no doubt the elusive Banksy is a very bankable artist. So when nine street art pieces featuring animals — including elephants, a rhino and even a cat — appeared sprawled across London, they brought in the crowds.

We’re following the trail to find out how the wow factor is financially impacting the areas they’ve been left in.

First, historic Guildhall Yard, where there are piranhas painted on a police box. 

Madeleine White from Hang Up Gallery is a Banksy specialist. “If you ask a lot of people to name an artist, often they can name Banksy,” she said.

“Culturally, he’s incredibly valuable, and it enters people’s lives in a way that it might not if it were hidden away in a gallery.”

The art is not hidden away, but the local authority — The City of London Corporation — has snapped up the piranha police box, moving it outside one of its galleries.

Culture chairman Munsur Ali said the piece was moved “for the public good” and to protect it.

“We are not in the business to support graffiti art,” he said.

So the council doesn’t support graffiti art, but it wants to protect and support Banksy. Why is that? 

“You’ve had 2,000 people come over here,” he said. “I’m hoping those 2,000 people would go and have a coffee at a local coffee shops and increase business for the local businesses.”

OK, so is that happening? Let’s head to the tourist area of Brick Lane, which is full of shops and global cuisine — and a Banksy, which features three monkeys swinging across a railway bridge. There’s even a tour group as we arrive. 

“We just walked down the street and it was there,” said one woman. Did she come intentionally to see it? “No, we’ve come for bagels.”

Two local men aren’t sure it’s boosting business. “People just stop there, they take a photo, then pass,” one said. “That’s it.”

Another added: “A lot of people come here, they lay on the stairs, they sit on the stairs. It’s not good for the business.”

But, if you’re off the tourist beat, like pub owner, Mark, the Banksy depicting a rhino mounting a car — five minutes from his pub — is very welcome. 

“He’s bought a nice weekday lunchtime trade,” he said. “Thank you very much. Please pop one on the side of a wall!”

And who owns that wall? Does that ownership technically make the art theirs? The rhino, which has already been defaced, is in Greenwich, an industrial area in the southeast of the city. It’s owned by the council, which is facing big budget cuts. Might this help?

Local Councillor Ann-Marie Cousins said it’s not clear. “We still don’t know what is going to happen with this, so we’re still thinking about possibilities,” she said. 

Other councils have removed Banksys from similar walls and sold them. Could that happen?

“Oh, I think all local authorities go through this,” Cousins said. “You sort of think, ‘Can we sell it? Can we leave it in situ? Would a museum want it? Would a rich buyer want it?’ All the ideas are up in the air, but we’re still thinking about what’s realistic or not.”

When Banksy works, people are keen to get a piece of it. In fact, a wolf in a satellite dish was stolen within an hour. The scramble to protect, sell or even steal them means they are undoubtedly seen as assets. 

Perhaps not quite what the artist — famous for being anti-consumerist — intended.