Someone is willing to pay about £100,000 for the Banksy on a garage in Port Talbot, an art dealer has said.
Garage owner Ian Lewis has received several approaches from private collectors hoping to buy the piece.
Art dealer and Banksy expert John Brandler said his client would offer a six-figure sum "because it fits nicely into his collection".
Mr Lewis is understood to be meeting the Welsh Government and Arts Council of Wales to discuss other options.
Mr Brandler said any offer his client was likely to make would be close to £100,000.
"He collects Banksy and he collects other street art, he collects a range of art," he added.
"He's got the grounds to display it from day one himself but I think he'd be more than willing to consider the social part of it as well."
The dealer said the collector would consider keeping the piece in Port Talbot for a few years as part of any deal.
"It could be a good way of drawing people to the centre of town, which would help the local businesses, because Port Talbot isn't generally considered a number one tourist destination, so it would help the local community in that way."
Whatever the outcome, Mr Brandler said it would most likely cost "tens of thousands of pounds" to move the piece.
One option could be to paint the back of the brickwork with a hard-setting resin, which would then allow part of the wall to be cut out without cracks appearing.
Mr Brandler said if the mural had been painted on a similar-sized canvas, it could have fetched up to £500,000.
"The fact that this is so big means most people in the country couldn't look after this piece if you gave it to them - and that's what has happened unfortunately to the owner here," he added.