It would be close break even IMO.
You can get lucky and get some good yellow saints, or not so lucky and wind up having to delete a bunch of blues and weak purples.
Plus going from AA5 to Dominion5 can take as much or more cards than going from Saint 5 to AA 5 it self.
It is all a bit of luck on what kind of saints your hero (Adamanti) has lined up.
For me, I rather build my Hero's as I go along and remove crap saints as they pop up. I find it more gem cost effective this way. If you don't plan to remove any saints and use what you are dealt with, then I would go the transfer route.
So far every transfer I have done have given me 1/3 yellow, 1/3 purple, 1/3 blues. My Pompey is a prime example of this as well as my Flavius which in both cases I transferred from other hero.



