That looks to me to be a standard door frame, no intumescent strips etc. They are not expensive. Is the quote for replacing the door as well? Its hard to see exactly what is needed from the photo you've supplied.
For reference for fitting a standard frame I would charge £80 and £80 for hanging a new door (labour only) £20 to £40 for rehanging an existing door depending on the amount of work needed. But I don't work in Brixton so couldn't help you there.
That looks to me to be a standard door frame, no intumescent strips etc. They are not expensive. Is the quote for replacing the door as well? Its hard to see exactly what is needed from the photo you've supplied.
For reference for fitting a standard frame I would charge £80 and £80 for hanging a new door (labour only) £20 to £40 for rehanging an existing door depending on the amount of work needed. But I don't work in Brixton so couldn't help you there.