Hence the requirement for all quickened spells to use the buying successes rule. Even mid-session.
Heck, ALL downtime rolls must buy hits, for that matter. Quickened spells are special only in that you must buy hits during play, too.
I may not have been clear, let me try again. Yes, I agree. The issue is that we know a PC's dice pools, we know a Contacts dice pools (Connection x2 as you informed me of above), but we do not know random non-contact NPC's dice pools. If a PC chooses to get quickening from that route we need a formula for that that is not GM fiat, since that can and will lead to wild inconsistency.
Edit 2: Unless you mean that the only non-PC, non-Contact NPC source that can be used is a named, statted mage with quickening present in the Mission where the quickening is purchased?
Well in the case of Increasing an attribute, the extent of the variation that is possible is +1 to +4. I'm not sure I agree that counts as the potential for wild variation.
So, sure there's the other spells that give bonuses that are not subject to augmented limits. What's to keep a GM from letting someone quicken Improved Invisibility or Armor on themselves with a ridiculous number of hits?
Since it's bought hits, the NPC spellcaster must have had a dice pool of 4xnet hits. Even if you want +5 to something, then the GM invented a NPC for the mission with 20+ dice pool. Is there wild variation between GMs thinking 20-ish dice is unreasonable for an unwritten NPC?
Maybe? It depends on what you call wild variation, and that's gonna end up being opinion based, rather than objective. SRM's already got a couple rules to address this indirectly. There's the In GM We Trust to allow a GM to insert un-written factors into the mission. There's also the In Player We Trust to be inclined to take their word for "that last GM signed off on it". And on the other side to bound things in is the rule about GMs not going overboard with rewards, like not giving players Lowfyr as a contact. Due to the requirement for buying hits, by the time a quickened spell is strong enough to be problematic it should be fairly easy for reasonable people to determine if the NPC who cast it had an inappropriate dice pool.
And more than that... unlike having say a Banshee LAV or being best buddies with Lowfyr, a quickened spell is trivially easy to just take away by any subsequent GM. All an astrally projecting NPC mage only needs is 4 dice in their Sorcery pool to casually rip the spell down 1 hit at a time. If a mundane even noticed what was happening (and that's a big if), there's drek-all he could do to stop it. Or of course, you know. The old "oops you walked thru a mana barrier. Lol!" trick in the GM book.