You mean Big Nikko?
Good FT scopes, although heavy. Easier to use straight off, should cover the full 10-55yds at ful mag and can be bought from about £300 second-hand. Mk1 & 2 pretty much ok, some mk3s have a few issues - search on here for details. New mk3s should be ok.
Focusing with Leups has to be learnt, and they can have a pronounced temperature shift. Ifyou want variable mag then you'll be after a VX3 20-50, fixed mag will be Comp 35, 40 or 45x. May need a close focus adapter. Expect to pay around 700 minimum 2nd hand.
How about a Sightron SIII 10-50? Around a grand, more expensive than the nikko, cheaper than a new Leup. Good glass, although narrow FOV (to my mind). Just get the standard scope, not the FT version, as some have found that they only range to 50 or so yds when hot.
It all depends on how much you have to spend, whether you want light weight, fixed mag, ease of use etc.