The best stuff doesn't come cheep but when you want your $30000 4WD to get yor butt home you don't want a $20 cigarette lighter job.The other system I have cost MORE.
Also, the more you spend the faster they work and they don't overheat. With tires that run around 30 PSI on the road the CO2 deal will have you running down the highway in about ten minutes or less. Think about it.
The CO2 is in liqued form in the tank with the gas in the area just over the top of it. Depending on the air temperture te gas in the tank runs around 900 PSI, the same as a fire extinguisher. The regulator brings it down to 0- 150 PSI depending on how you set it. You get the tanks filled at any firematics place that does extinguishers. You can tell when the tanks are getting low by weighing them, difference between empty tank and full one, same as propane. I use mine as a back-up in case the air pump on the motor goes.
I will admit that big air cost big bucks but it will last a lifetime.you buy it one time, thats it. If your at home and your brides car gets a flat, you're ready to put a plug in and reinflate. They claim that the CO2 will even put a tire back on the bead if it pops off. Try that with a cigarette lighter job.
Hope this helps. If you can afford a $500 reel you can protect you truck with a $400 pump.