I remember reading a Consumer Reports article that said helmets that don't meet basic safety standards still end up on store shelves at an alarming rate. These tend to be no-name or unrecognizable brands, usually at department stores. Their recommendation was to buy a reputable brand. If you look inside the helmet, it should have a sticker stating that it has met U.S. safey standards and also a unique number (like a serial no.).

In terms of cost, I'm not sure about the other brands, but I do know that Giro's top-of-the-line models are made to withstand more impact than their cheaper models. Yes, they all meet the basic safey standards, but their more expensive models far exceed that, so in a way, they are "safer" than the cheaper ones. I may be different from the rest of the herd, but if it's not going to create a financial burden on me, I tend to get the ones that can withstand more impact. I've literally ruined 2 helmets already and if it wasn't for them, I'm not sure I'd still be here. Safety gear is not an after-thought for me.