A bit of digging reveals quite a few scam R44s supposedly for sale in the UK.
Some key points to look for,
No external photos.
Foreign Reg aircraft in strange places.
Check where it is supposed to be kept really exists.
P*ss poor use of English in the replies you get to emails (worse than mine).
Google the Postcode for the seller and see if it matches their address.
Check G-INFO or the Faa N registry (or local registry of choice) and see if it has been de registered or even exists.
Google the Reg and see if its got any crash history.
Gary