Some of the amateur rockets can get way up there. The bigger ones, which require FAA approval for launch, have set records from 50 to 70 miles high. For $100, you can get a rocket kit that, with the right motor, will easily go 7-10,000 feet, though the motors aren't sold in hobby shops.
Yes, I know rockets can get very high. But not bottle rockets.
Were the MythBusters in the area at that time? ;-)
>> ...the motors aren't sold in hobby shops.
Aren't those the ones that require you to have some kind of Federal cert just to buy them?