Ballpark cost for plumber to fit these things:

[strawlight]

Replace radiator (small, approx same size but different style to the old one - we have bought the new one)

New small basin and pre built vanity unit for downstairs loo. Might be a faff on with pipes in a tight space.

Had a quote which I think seems high so just wondering…

Depends on the area you live in. The amount of time it will take (you say yourself it's a faffy job). Have you had more than 1 quote so you can compare??

Just got one quote from a trusted plumber that we’ve used before. We’re up north. I’d rather use him as he’s nice, local and professional and I trust him in my house, but I really shopped around to get the best price for the radiator and unit/sink, and the quote is for way more than I’ve already spent.

So taking the bathroom stuff out of the equation for now, I’m just wondering what people have been charged for radiator replacement (we have already bought the new radiator so it’s just the installation of it and any boiler related “tuning”)

Replacing radiator may mean draining down the whole system if it can’t be isolated. If it can be isolated I would expect to pay around £150 .
Bathroom , labour only, would expect a day rate of circa £300
Buying all the parts yourself means that the plumber can’t make himself any profit from marking up his trade price.
What are you expecting to pay ?

I think that if you have a reliable and trusted plumber willing to do the work, you're winning. Unless the quote is actually ridiculous.

Because finding another reliable, trustworthy AND cheaper plumber will not be easy. If you can find one at all.

Yeah I think you’re right, even if it was £100 cheaper it’s still the hassle and the unknown. At least with this one I’m comfortable with him being in the house and we know he’ll do a good clean job. We’ve accepted and he’s coming on Tuesday. Fingers crossed all goes to plan!