We're interested in a new build that won't be ready until August if next year but the builders want missives concluded now. They are saying there no room for manoeuvre (we have a property to sell that has a full valuation home report - we're in Scotland). Has anyone been in this situation and managed to negotiate? Maybe paying a higher reservation fee or something? Or is it best just to walk away as there's no way I'm concluding the sale so far in advance.