It's just made without the usual ridiculous mark up by the seller, it may well be made in a different country where labour/materials are cheaper, that may explain the price.
I don't know you'd be any worse off with this than 1 of the big names, as I've never yet heard of the big boys in this game fixing/replacing under warranty, even when there are issues like breakages leaks etc.
Personally I'd go for a airtec, very solidly built, not the prettiest but do the job, unnecessarily heavy though!!
tabetha