There seems to be a another surge of these things appearing with grandiose claims. It’s certainly a scam at £136 and I would say £50 is too much. The claim of having a usable 4K is probably an abuse of an artistic license.
If you’re looking for something of this ilk I’d look at the Eachine E58. They are a toy, like the one you linked to, but considerably less and it’s claims are honest.
If it’s still available at that price on Payday, I might try it out…
As an aside, I use an Amazon discount site called vipon.com, and they have 3-4 similar “toy” drones at 70-85% off (so all around the £35-50 mark)… None of which I’ve ever heard of. All look like knock-off MAs. Which I’m sure they are.