He will probably shut up shop and open up again in another name 
i hate guys like that why not be honest about the thing or say that am not %100 sure and sell them on at a fair price instead of guys like yourself been ripped off 
I also fell for it ! I paid £140 for mine and the guy had a disclaimer on it saying it was fake but silly me didn't read it , they are made in the USA somewhere.
It is well made for sure but it's not a Helix stem , Helix are stamped underneath.
Helix haven't made stems for a long time and not making anymore , just dropout savers and some seat post clamps they have left, I spoke to the guy at Helix a few months ago,
These stems need to be sold as repop and not originals, buy it now £100 free post I think is their true value , they still use high quality components and good engineering skills
