It really depends on what format you want to play. I have been playing edh for a while now. I built Niv Mizzet with the intention of someday owning Jeleva. My friend is over playing against storm as I have built version after version picking up cards along the way..
I'm about 80% of the way to moxnix's deck, and I know there are cards I'll never buy... every dollar spent speeds it up, but every dollar not spent slows you down or gives you a greater chance to brick..
I feel a tier two dedicated storm deck is still looking north of $1000 and bricks every couple of games.. I have pulled some sweet wins off though and I'm still hooked...
Mana
Artifact Mana
Card Draw engine(s)
Wheels
Tutors
Counterspells
a Mana Engine (
paradox engine / MoM / Isochron +
Dramatic Reversal)
And a finisher (Lab Man if your draw engine is good enough / aetherflux res / Tendrils)
Forget most of the rituals unless you're in black.
High Tide only if you're running several of the "do something and untap lands" cards
Most important is Mana base + Artifacts that net on storm turn +
chain of vapor or hurkyl's floating Mana bouncing your net+ rocks and replaying them will give you a pretty decent
mind's desire/other storm effect.