Hmm expensive... the ultimate sacrifice? Devoting yourself to someone else entirely? If that's not a Nun though I'm not sure what this symbolizes, cap seems more like that of a cook, and The A, and surrounding... I'm Pecheneg-level baffled here too.
Or... could it be a play on grades? All you need to sacrifice to ace those A's? Sheath yourself and spend your days in a keep of faith...? Always interesting with these symbolic ones.
-cd-