Living Wish, +1x Mana (tapping the well), +2x mana (activation cost) = 5 total mana to tap down a Trinisphere for a turn.
I, for one, would rather just side in Oxidizes. It's a decent 1-of in the sideboard, and it might save your ass sometimes, but not TOO frequently. If you need the room for something else, I wouldn't be too bothered to cut it.
Good thought, though. Now I have a use for that previously useless Foil Well I've been stuck with for God knows how long.
I don't think Living Wish is necessarily a card that would be in any of those decks, and paying 4 + a land drop is not condusive for a speedy turn. I primarily play Affinity, and I guess what I'm wondering is whether or not it would be worth to run two in the sideboard.
Barry