Argh, just received the buyers enquiries...all 36 of them! Have answered them all I think now, although still a little stumped by the one asking 'can the seller justify the increase in value in the house since they purchased it 11 years ago?' Is this a normal enquiry to receive?
I wanted to just put 'no', but dh thinks we should put something about the fact we put it on the market at a value decided by four local estate agents and that as they, the buyer, offered on it, they must have thought it was fairly priced?! Or, maybe just 'duh, market values have increased...' 
!
They have also listed all the minor repairs their survey highlighted as enquiries and asked for us to arrange/pay for an electrical survey - does this mean they are going to try and negotiate on the price? I hope not as a refusal often offends!
We had another offer (for more than their offer) the day after we accepted their offer, but declined it and stuck with them as we'd said yes and thought it was the right thing to do, so I hope they don't mess us around now!