The main cost driver is Zeus: the SP or Alternate Art version (OP11-106) is what inflates the budget, though the regular rare version is functionally identical and costs well under $5
To determine the total cost of a spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions (such as that of Grounded for Life's first ability)
At their core, Ramp decks generate a tremendous, mostly permanent, mana advantage which they leverage to kill the opponent
This deck is still looking for the right build, but it holds a lot of promise
The price of Yuna would continue its upward trend until June 12th, peaking at $27.38
If you need a board wipe, Nuclear Fallout should have you covered