Most of the plumbing I do sits inside a bathroom or kitchen renovation: moving waste runs for a new shower position, running pipework to a relocated basin, or connecting a new bath and taps. It is fixture and pipework plumbing rather than gas work, so it is priced and quoted alongside the bigger renovation rather than as a standalone emergency callout service.
Getting falls right on waste pipes is the part that gets rushed on a bad job and causes problems years later, usually as a slow leak inside a wall or under a floor that nobody notices until the damage is done. I test every connection before tiling or boxing anything in, so problems get caught while they are still visible and easy to fix.
Plumbing work is usually included in a bathroom or kitchen quote rather than priced separately, though standalone jobs like fitting a new tap, basin or shower valve typically run from £120 to £250 depending on access and whether pipework needs moving.