So, we bought a 1930s fixer upper last year, London outskirts, 5 bed.
So far we have paid:
£4.5k for complete rewire, plus £1k for light fittings (supplied by us)
£4k for a new boiler and full central heating system replacement, plus £1k for 'nice' radiators
Approx £400 per room for replaster
Approx £500 per room for redecoration, including paint (but not including my more expensive wallpaper choices 😁)
£3.5k to fit a new kitchen (supplied by us), including opening up a larger window aperture and fitting new window (supplied by us)
£1200 for a quartz worktop, supply and fit
Over the course of the work we've also spent maybe £1500 having waste removed.
We have quotes lined up for a new en-suite (£3.2k plus fittings, which I'll buy separately), boarding and tiling our hallway floor and sealing our kitchen floor (£1,200) and a new bathroom (£4.5k plus fittings).
I've not included the cost of fittings because it's a good way to control the budget - with all of these things you can spend an absolute fortune on something or you can go relatively cheap (or get a bargain, or reuse existing, etc etc). Also, a dodgy builder can make a lot of money on this too. These are the pure costs for the labour on the house.
I've also had a wall knocked down and RSJ inserted before - came in at about £1700, including knocking out, the joist, boxing in, making good and building regs application costs.
Hope that gives you some ballpark figures to go with.