Hi gordons
Cor.... Difficult
If it was me I'd go for £4 a bay window, £3 for a flat one plus £0.75 for each extra piece of glass/window and £5 for a conservatory and £7.50 for a big one.
It's an experience thing that's almost impossible to guess unless you see the job.
That's what I'd be asking for down here in the South East in Brighton but prices vary according to area.
Ugh... that's a real difficult one.
Better to over price and loose a few than to under price.
I'd be thinking 'help' too.
Cheers
Ross