Im in a slightly different position in that my plan/plans is/was to replace my own turbo.
However I also found that most either didn't respond or didnt have prices on their websites and when you called them wouldn't give you a price or were very vague.
Then there was the surcharge anything from £100 - £250, and you had 14 days to return your old unit , looking at some
reviews some people had lost their surcharge because the company they used then stated things like the exhaust housing was cracked or otherwise damaged.
I could have gone brand new for around £800 and I also ruled out anything that looked too good or cheap.
I wanted a Mamba hybrid as they had very good
reviews and their pricing was spot on - they never replied to my emails.
So in the end I seemingly foolishly went with Venom - they have no time frame for returning the old unit, so I paid up in full on the 14th of the month, and had an order confirmation within hours, but have heard nothing since.