The thing is, without auto learning of skills there is a natural disadvantage to certain classes, namely mages. Mages are pretty much shafted in FFXI, a melee can go from 1-90 with AH rentals (buying gear on the AH then selling it back later at either a loss, a profit). Mages also need to AH rental BUT they require scrolls which once used cannot be sold, once it's gone, it's gone (and for questable items can only be obtained once).

If you're talking the same system as WoW where you run off to the NPC every so often and buy skills for currency, again mages would be shafted as they generally require a *lot* more skills than a melee, so it would end up being more expensive for mages to level up than for melee which is hideously unfair on mages.