Usually between $5 to $10.
Yes they do
Call them and ask!
$8
Depends on the connections.
12 grams are non refillable.
If it has threads on the top, you refill it like any other tank by taking it to a sporting goods store or paintball field. If it does not, then it is a disposable, and you cannot refill it.
In most states you only have to be 18.
Dicks, any paintball shop, and Gander Mt.
There are a few places that will fill your CO2. Local paintball stores will, as well as their fields (if they have one). Places that refill scuba tanks will as well. Finally even some hunting stores will.
Yes! some walmarts or Shore Sportsmen will, as well as any local paintball shops and fields.
You can purchase them at most sporting good stores like Dicks, Walmart, Big 5, Cabelas or Bass Pro.