Not buying it. It was a typical weather balloon carried on the jet stream weather currents.
It would have had a massive engine and propulsion system to direct it to wherever the Chinese wanted it and at an elevation of 58,000 to 60,000 feet, there would have been little oxygen to keep those engines fired. And that would have to include the additional fuel source.......
It apparently had a large truss structure (aluminum? carbon fiber?) with solar panels. That assembly could probably be used as a rudder and sail to veer away from the natural direction of the the jet stream. For altitude control it probably had a good-sized tank of compressed helium, so it could rise and fall to take advantage of the various directions of wind currents at different altitudes.
So, along with a multi-compartment balloon (probably at least 200 sq. yards of fabric) and lots of rope, add in a bunch of solar power regulators, cameras, computers, navigation electronics, uplink electronics, and likely a dozen other sensors (ground penetrating radar?, UV?, infrared cameras? ...), and I'm sure it added up to thousands of pounds.
They needed a pretty good setup to do a respectable property inspection before they take possession.