Sorry to bear bad news but replacing a bay is the most expensive/hardest window to replace.
They have to be measured accurately as no 2 bays are the same.I.e the angles are different/each side could be different lengths.
The removal and fitting isnt straight forward either as whilst removing, the bay has to be supported(usually by acros) so as not to collapse.
It also depends on how high the start of the glass is from the floor as to whether you will need toughened glass(under 800mm = more expense)
Been out of the game for a few years but I personally hated doing bays.
I would also use a decent local chippy as they usually take more pride in their work(not thrashing around and leaving untold amount of mess everywhere and taking shortcuts because they are paid by the day…not for a good job done
hope this helps a little