Weather balloons?

Question

1. How much do weather balloons cost approximately?

2. Approximately (I realize it varies between models/brands) how many liters does an average weather balloon hold?

3. When filled with gas (i.e I assume helium), how long do they typically stay in the sky for?

Answer 1

1. Found a site that has then for 19.95-79.99

2. The body of a weather balloon is usually made from latex or a similar flexible material. It is inflated with hydrogen or helium, with varying levels of gas being used, depending on how high the weather balloon is going.

3. When the balloon reaches a certain altitude, it explodes