Exactly. And even if it's tested well I really don't see why I would want to pay upwards of $100 for a smoke/co detector, when I can get them for about $10. It

Exactly. And even if it's tested well I really don't see why I would want to pay upwards of $100 for a smoke/co detector, when I can get them for about $10. It's a device you buy and don't want to use, ever. I'd rather spend the money on routine checks on possible CO sources (oven, heater, ...).