While the Adept is hardly an exciting card, it's incredibly functional. In Commander, the Adept fits into a wide variety of decks, from ones that care about having a bunch of Wizards on board (Azami, Lady of Scrolls) to those that can abuse enter the battlefield abilities (Brago, King Eternal). It also works well with popular Commander cards such as Patron Wizard and Riptide Laboratory.
While the foils of a lot of useful commons and uncommons tend to get out of control price wise, copies of foil Aether Adept can be had for about a dollar. They're probably a good investment, as this card will always have some demand going for it.