Tell them you'll do it once the painter's finished!
Look at it - when was the last time it was done? If it was trad, they needed sky-hooks.
You'll have to go along each level of panes twice, frames then panes, then down to the next level to do the same. Work out your price from that but then add on time for cleaning out your brush at least once every level.
It's not too clear, but are the sloping panels framed or are they overlapping
