Card Advantage Mono-White decks simply do not get good sources of card advantage, so we had to go pretty deep to figure out a way to draw cards
This may or may not be $25 like Atraxa, but even if the 3 Wizard commanders are $30 between the three of them, the deck is still going to be in high demand
And while many were clamoring for the ban of Gran-Gran or to hit the Izzet Lessons deck in some way, it seems that the meta simply evolved to make that deck less dominant (Elementals and Reanimator are both strong against it)
Although Commander Masters gave a little love to colorless commanders and we can have legendary vehicles as commanders, none of these are very exciting, or they have poor support in only colorless
Key factors that determine value beyond rarity include: The Reserved List: A promise from WotC not to reprint certain old cards, creating a finite supply
Four mana for a 5/5 flying is okay, but a bit slow, and crew 3 isn't great for a 5/5 just two power increase