Unsupported chimney breast in house I want to buy

[Confusedanddazed]

I'm in the process of selling the family home and buying a place for me and my DD and have found the 'perfect' house that I really want to buy.
It's an old house and I had a damp and timber survey done which showed patchy damp but nothing too serious - so far so good.
Then the guy doing the damp survey noticed that there had previously been a chimney breast in the kitchen which had been removed (save for about 4" of original chimney breast) - he had a quick look under the floorboards upstairs and couldn't see any steel suppport for the rest of the chimney stack.

This alteration was not done by the vendors and there seems no sign of any building reg certificate.

I'm having a building surveyor go in and take a look but I've no idea how big a job it is or how much it might cost.
Has anyone got any experience of this at all?

We got a quote of about £3k to fix an unsupported chimney breast about 3 years ago. And that was assuming the worst and no support at all.

We paid £3000 for a similar chimney breast repair (but we replaced the chimney breast rather than put in steel supports)

Crikey!

Our previous owner removed the chimney but fortunately he put the support in - we had a support done for the roof in 2004 and a tiny bit of steel cost £1k so I'd think 3k was near the mark.