Answering some questions.
The weather balloon we used is rated for about 100,000 feet before bursting. We believe to have reached a little over 90,000 feet in altitude. The GPS unit does give altitude reports, but we're having difficulty getting it from the service. It usually takes about 3-3.5 hours for a balloon to reach into the upper atmosphere before bursting. Depending on your chute size, it takes about an hour for it to come back down to the Earth.
We did not contact the FAA, but was worried about the balloon traveling over an airport into commercial or federal air space.
The industrial grade balloon costed about $60 and the helium used was about another $60. The balloon is rated to expand to 20 feet in diameter. You don't want to fill it all the way though or it will burst prematurely. The optimum size is to fill it about 6 feet in diameter. This will give it enough room to expand as the atmosphere gets thinner and will allow you to achieve maximum altitude before bursting.
Link will hopefully come Monday.
Once you passed 18,000' MSL you were in violation.