This is a nonsense (you hope).
Your standard terms and conditions of contract make it clear that any representations made prior to any executed contract are of no effect and were not relied upon by the Parties. However, you are concerned that you did clearly value the property. You’ve had conflicting informal advice as to your liability on this aspect from a couple of lawyer friends.
In any event the (mis)representation point is your main defence.
Beyond that you always suspected that the Holdens implicitly realised that you were aiming for the top end of market possibilities in terms of price.
Looking back, you realise that you may have been a bit ‘over the top’ about the chances of achieving your suggested price. In regard to the allegation that you did not inform the Holdens about the downturn, you simply did not wish to give the appearance of appearing negative about the problematical market that then ensued. In any event you could not be responsible for market movements.
To reduce your premium you agreed to a PII excess of £35,000.
Whilst finances have been very strong in recent years, you are very concerned to minimise all future expenditure in the light of the current market circumstances and significant reduction in income.
Notwithstanding your view as to the merits of the Holdens case, to avoid the risk of legal and associated costs, you realise that you may have to pay a significant sum to the Holdens – but the less the better.