Weather+Balloon

Cost of Weather Balloon Cost of Balloon: 1 cubic foot of helium lifts ~0.067 per cubic foot, and 1337Arts recommends a 350g balloon or greater. 0.067 lbs = 30.3906 g, so a 6' diameter balloon, 18.84ft cubic feet would get you 1.26228 lbs of force or ~572 grams, which is plenty. We can get this for $24.95 from here.

Cost of Helium. The average cost per 15 cubic feet of helium is $40, or ~$2.60. We need 18.84, so about 19 cubic feet, which would cost $49.40 on average. Rentals would be cheaper, this is the whole tank.

Cost of GPS. A SPOT Satellite Messenger with one year of service costs $269.98, which is way too much. The Motorola i290 phone costs $29.99 with a 35 cents a day, which is much, much cheaper.

Cost of Accessories. Antenna - Can be taken from an old router. Battery - Lithium Ion around 9v battery, can be bought for about $2.40 Beer Cooler - I don't know.

Cost of Camera. The Canon A480 is the cheapest I could find that is compatible with the software. It costs $92 from here.

Total Cost: Balloon: $24.95 Helium: $49.90 GPS (1 day): $30.34 Battery: $2.40 Camera: $92
 * Total:** $199.59