Perhaps I'm not understanding the card correctly. Hypothetical situation: suppose the Wizard has 3 Mana Crystals in play (current channeling 13). If they use this card, they pay 10. On the following turn, do they channel 15 (their current + 2), or do they channel 28 (their current, plus current + 2 from Meditate)?
If the former is correct, then this card would basically be worthless. I would never play it over a Mana Crystal or Harmonize. If the latter is the intended effect, I could see it being used in the right deck (especially if it has the right subtypes and traits; e.g., it would probably be a "mana" spell with cost decreased by Arcane Ring). I feel like you would maximize its value by over-committing to channeling effects early on.
I don't mean to hijack, but I'm curious what others think would be a fair for the following hypothetical card, which would serve a similar purpose:
Name: Black Lotus
Type: Incantation
Target: Mage
Action: Quick
Cost: 0
Trait: Novice
Text: Add X mana to target Mage's mana supply.
Basically, how much mana is 1 quick action and 1 spell point worth? Meditation Amulet nets 2 mana after 1 quick and 2 full actions, but has the potential to keep providing more mana (especially during actions that might otherwise be used ineffectively). Mana Crystals might net an average of 3 or 4 mana over the course of the game, but could net more and provide lasting advantage in a long game. By contrast, this hypothetical card can only give the one-time boost. Would you use up an early game action on this if X were only 2? Would it completely replace Mana Crystals if X were 4+?