THE most important part of any GM-Player relationship in any RP game is that everyone shares the same mental image and broad understanding of the "game world". Not just the tactile, the physics (including "magical" mechanics) and geography, but the zeitgeist - the philosophy behind and worldview of the populous as a whole.
So, if someone does something, the reaction from NPC's "makes sense", and catches no one off guard or by surprise - or when it does, it's because it's supposed to.
That's an interesting plot complication, and one I had not looked far enough forward to foresee. But you're right.
Debated how "hands-on" this Mage would be in training the prospect/merchandise - much would depend on the value he's adding to the initial price, and how "in need" he is. His motivations would not be purely mercenary - something in his background led him down this path, and I'm still toying with those formative experiences.
In passing I've also weighed the vision of an elite (and secretive) boarding school cum apprentice factory, overseen by over-paid mundane outcast scholars, where small classrooms of the variously gifted would learn all they needed to become either choice apprentices or lab assistants - but now that you mention it, that would be about as dysfunctional as it gets.
(Altho', maybe a self-respecting Tytalus would welcome that as an added bonus... still haven't decided on this guy's House.)