House sale stopped/request for refund of survey fees

I live in Scotland and had my flat up for sale, it was on at a fixed price, an offer was received below the fixed price and in order to make offer serious a survey was carried out on my property.  I instructed my estate agent to continue to market the property for me and to continue to send viewers to the property so as to achieve the fixed price.  The potential buyers were aware of this. 

My circumstances changed and I therefore did not go ahead with the sale, I did not have a "conditional acceptance" letter sent by my solicitor and as far as I am aware at this stage there is no binding legal contract between parties.  At this stage both parties can pull out without penalty?

I have since received 3 months after the sale was stopped a letter from the potential buyers solicitor wanting me to pay for their survey fees (£200).

Am I legally obliged to pay this, I dont believe I am as there was no legally binding contract?

Can anyone help (under Scottish property law) please?

Thanks