You don't need Angel Ray to HS. Seriously, cleric-priest-bishop will be the cheapest class potion and equipment wise to play. The only 4th job book that you should worry about is Advanced Blessing which isn't all that expensive last time I checked.
As for "fun" classes that's subjective, and none of the really fun ones are cheap to play (because they're fun and therefore demand for relevant items is higher, making things more expensive)