Youd like to play this red enchantment with commanders that have a built-in mana sink, or commanders that use the mana to create more creatures, creating an infinite combo (Sliver Queen, for example)
Never analyze a card in a vacuum
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It also shows that any copies that have been listed closer to the visible low price are being snatched up, and that theres real demand for the card
Instead of paying the full mana cost, you could put a lot of cards in your graveyard (which many competitive decks tend to do) and pay the minimal cost for each of them
As of the writing of the article, the prices on most of the decks are equal, except for Eldrazi Incursion, which averages at twice the asking price of the other decks