It isn't all about meeting the standards. It is about the best protection you can get for your head. Expensive, well known branded helmets are the subject of millions of pounds worth of researchand development annually. They are constantly being improved. They are companies that you can send your hat to if it needs scanning for damage after it's been dropped. These top manufacturers don't just meet or conform to standards, they exceed them in every way.
This is your head. I am a motorcyclist as well and we have a gold sticker with motorcycle helmets that says they conform to the higher standard. I would still never but one of the cheaper ones. I have seen horrible damage caused because savings are made through lack of attention to seemingly non important parts.
Riding hats are no different IMO. I would rather spend a month eating nothing but toast to be able to afford the best hat I could buy, than have a consultant tell my family I would have been ok...but the hat I was wearing failed!