I have been offered one through work for £50, they look ok but I have no experience of them so would appreciate any feedback or if there is a better option in the same price range.
You can Minger, but it all depends on quality. I cant comment on the Scorpion Huntsman, but I have a Galaxy 3000 helmet (Ebay special) and it's total crap. I was given 2 other types of auto helmets by friends who "Upgraded", and again both of them were OK, but not brilliant.
I bought a new Cigweld helmet last week and its the best thing I have ever used. 10 times the helmet compared to the others, and I'd never again buy on price, especially since I only have one pair of eyes.
One of the main things that seperates a good one from a bad one is the reaction time of the cartridge, check some different ones out and see thee difference between the quoted figures. My Siflite one has a reaction time of 1/10000 sec, I've sen some at 1/1000 sec so ten times slower.
I like it, it's very responsive even on low amp tig, the gumpf says 50A> but it seems to work ok below that. If you compared it to an Optrel or Speedglas you'd notice the difference in build quality etc but for the price I don't think you'd get much better.