Also, there have been some exceptions in recent years, such as the Flutterstorm promo from Modern Horizons 3 , which was a pricey card at the time of release and still sells for a respectable average of $6 at the time of writing
getting 6-9 mana for an investment of three mana is the bit that most decks are interested in
eBay charges around 1213% in fees , which are automatically deducted before you receive payment (deposited directly to your bank)
Five mana is certainly not cheap, but its pretty strong to be able to pop a Jace, Architect of Thought or a Stormbreath Dragon on the way down and threaten to generate further advantage or even win the game on its own if left unchecked
Remember that phasing is a static ability, it does not know how to trigger
Mardu If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time