I’ve done a bit of digging around into UK case law. Not sure whether it’s worth the hassle, but there’s a legal term ‘negligent misstatement’ which may be applicable. The tricky part is proving intent, if I can demonstrate that the seller has deliberately concealed pertinent information and massively overvalued the property… they might be liable for my costs.
Lots of ‘might’ in there though, and proving intent can be difficult. I’ve instructed solicitor to cease work on the exchange of contracts; wondering if I should say anything to the seller / estate agent. They wasted my time and probably £1000+ of my money, and I definitely feel a petty impulse to waste theirs in turn.