Get a cheap helmet so you don't damage a good one when you fall off. Nothing more aggravating that digging holes in a high $ helmet.
Get DOT get what you like. 1/2 helmets work just fine. There is absolutely no well premised empirical data to determine fatality rates per helmet style. Snell IMHO is way to hard and will rattle your brain while breaking your neck. I would stay DOT.
