I was told to budget £50 / m length to remove all existing stuff and to replace with new.
That is for Soffit, Facia and Guttering.
Bear in mind that Black/Brown Soffit and Facia is more expensive than white.
Guttering is same price no matter what colour you go for.
Check how deep the replacment soffit/facia is... the thicker the better, brand names obviously cost more etc.
I had 21m done recently... cost me £750. Although this was on a bungalow so no scaffolding etc needed.
This was using a local roofing company. (Man and his son).
We got quotes off a local company that do double glazing, conservatories, etc.... £2500...
although he said he'd come down to £1500 if we gave him the business that day (his year end).
He said if we went to one of the big nationals "Everest" etc then we'd be looking at £5000.