Know Your Opponents Deck: Understanding common strategies in the metagame will help you plan counter-strategies
What should be in your MTG deck
Wizards is first mostly because it is very upgradable and has a lot of immediate value, but it's the worst deck in terms of building a good long-term Commander collection, thanks to having poor lands and artifacts
Where prices take a jump are in the other monsters that populate the deck
Otherworldly Gaze If you count Surveil spells as self-mill (and I do, given how rarely you see triggers that care exactly how cards end up getting from your library to the graveyard), then Otherworldly Gaze is as good a choice as any for the most consistent, efficient, no-bells-and-whistles version of the effect
They will, however, fit very nicely into a MtG fat pack box