A Window of Opportunity

Some curious locals who live near Wallasey Town Hall have approached us with further enquiries about the case of the window frame that fell from the south annexe building on to the street below which you can remind about here :  A Sick Building for a Sick Organisation

They have also provided some handy pictures capturing the equipment that used to undertake the repairs and a close up of the work that has since been undertaken :
Observers tell us that two labourers used the mobile platform to screw L brackets into the rotten window frames (!) to stop one of them falling out again.
Let’s hope cash-strapped Wirral Council did everything they could to procure the best value for money for the job and it wasn’t a window of opportunity for a contractor to make a killing.
Anybody care to make a guess as to how much a job like this might cost ?
a) £1,500 ?
b) £5,000 ?
c) £8,500 ?