The thing I don't like about cheap helmets is the difficulty of adjusting them to get a good fit and they rarely feel comfortable to me. I'm not one to spend a lot of money on anything but it's better to spend $200 on something you'll actually wear than $20 on something that you won't.

I don't remember what I spent on mine but I'm sure it was well under $100. Probably between $50 and $75.