In PnP empower is +2 spell level and maximize is +3 spell level which translates to +10 and +15sp, but here those feats have much bigger impact - in PnP maximize is less than double damage (because average 1d6 result is 3,5 not 3), and in DDO most spells use weighted dice, so translating maximize as max dice result would give only about 30% increase in damage.
Inability to efficiently use maximize and empower on low levels is very PnP too - you have to be lev 5 to be able to maximize a cantrip, lev 7 to maximize magic missile - so you will waste a highest level slot to cast basicaly useless spell. It starts making any sense at higher levels and with some PrE (yes I know, damage casting in PnP is pointless anyway), exactly as here.