The "waste of money" is a relative term for people who love to speak in absolute terms devout of consideration to whom the advice is for.
Co2 kits in general cost more in the long run due to the limited life of the co2 cartridges and frequency of changes but Bear in mind, before any of us drove sports cars, we all owned a junker or beater to practice and learn on. To me, time and experience is worth more than just going out and getting what is perceived to be the best while having zero experience to fully appreciate these tools.
I often chuckle at guys who have these big 150 piece tool kits to work on their cars where in reality a small set of ratchets, a few wrenches, a torque wrench, two vice grips and clamps are all one generally needs to get the job done.
I encourage you to get a kit and figure out what works best for you. High tech isn't for everyone and you would only have spent $50 versus $200 to work that out. Best of luck.
"I am Groot", the faithful protector