Same with the knapped glass points. I wouldn't hunt with them because of the risk of glass shards in the meat, but that'd be one nasty war arrow.
Grasshopper, that same seller offers them without the blades as "target arrows".
Edit: I just noticed something else. They're fletched with duct tape. Again, not a bad concept. I've made arrows from hardware store dowels with sheet metal broadheads and gorilla tape fletching. It works, but I'd never try to sell such a thing. Come to think of it, he might be using plain hardwood dowels for shafts. He sells them in packages with 80lb bows. That can get dangerous.