I have the same problem, I took out and installed like for like: -
*1400mm Acrylic Corner Bath (including one hole mixer and cable driven waste)
*1000mm Corner Shower (including tray, waster, valve, fixed arm and head, extra hand shower and hose including small pipework alteration)
*600mm Basin (including single lever basin mixer, waste, semi ped and chased out wall to hide pipes for new wall hung look)
*Concealed Cistern Back to Wall WC
*Monsoon 2.5 bar Pump (a new addition obviously)
And swapped out taps in two other rooms.
This is my first Private Job (as a favour to a friend who is a builder) as I normally do pricework on site which is a lot different in costing. I had a look elsewhere at other's prices and £800 seemed to be the lowest I should go in at????
I took £300 before i started and now they want to know how much more they owe? I don't know what to say, i want to do it cheaper than a normal plumber as it's a favour, but what would a plumber normally charge, is £1000 the norm for this amount of work? All top end designer goods too.