Looks a bit iffy tbh. Considering that model on the Apple Store is nearly £2000. If your thinking about buying one I'd advise against it. Could be stolen at that price. There's the old saying "If it looks to good to be true it probably is".
I mean, you could meet up in a public place and do a full unboxing and setup. If it works, might be worth it. However, I do agree with Matthew.H that it's most likely too good to be true based on pricing vs. pricing at Apple.