Underlay (foam crumb solid) £3-£4 per m²
Don't like the 'waffle type' u/lay
Fitter charged £40 per room and £50 for stairs
Price included all the gripper rods and the metal bits in doorways (forgot the name of those)
I got my carpet on offer for £6 per m² and free delivery.
Best to measure the room and shop around for quotes as it varies considerably from shop to shop and offers available.