I have alllllmost (one mirror to install, one cupboard door to paint) finished having a bathroom installed. Fittings with discount came in at ~6k; total job was golf club thread worthy. But I didn't splash out on the £400 shower shelf I was looking at, so it could have been worse.
5k is pretty standard for a bathroom, I think (supplied/fitted.) maybe even at the lower end - people spend packets on their bathrooms.
we got ours done for 3/4k in the end (with a lot of tiling) but the three quotes we got (before we used our usual guy) were around 5/6k.