Let me put it that way.. if the 299 solo to you is nothing but just a cheap drone and if it crash, it crash and you will just move on and look for another drone, then you are right, the 80 dollar seems a bit silly
Yea, I previously gave the analogy of if you were given a car, would you not bother changing the oil because the cost of doing so is significantly more than your original investment in the car?
The Solo is a very specialized, capable aerial photography platform, being practically given away because it's basically unsupported and "outdated" (only in terms of hype, not actual capabilities). If someone buys it just to fly around for fun until they crash and then toss it in the trash, then yea, an $80 GPS upgrade is hard to justify and, honestly, not even needed. If they bought the Solo to do aerial video, then an $80 GPS upgrade to gain better accuracy and reliability is easily justified.
To each their own.