Peugeot 407 turbo

On that engine it's usually not just the turbo that's needed!
Well known in the trade,
Problem being oil supply to the turbo is the cause of failure,
and what it needs is an engine strip down and clean.
Carbon build up blocks the oil passages and restricts oil flow,
there's a small mesh oil filter in the oil feed that can completely block!
Problem is so bad that many garages just will not fit only a turbo as it's a safe bet you'll be back soon with your new turbo shot from oil starvation.
And I've heard turbo suppliers are now offering NO guarantee on new turbos unless proof of engine strip and clean.
So this is not a cheap job,
Which is why there's so many of these offered as spares/repair.
Or scrap!
So without an engine strip and clean if you go for the cheap option and just fit a replacement turbo whatever that costs you it's money down the drain.
The turbo will fail.
Not trying to scare you,
Just trying to save you money!!
You don't want to do this job twice.