Which mage class is worth to invest empress set on?

Less than I'd tremulously expected. I got the armor pieces for 30-35m apiece -- except the shoes, which had slightly below-average LUK and thus cost <20m, and the cape, which I haven't got yet.

//edit: To be fair, this was pre-Luminous. Dunno if you can get everything for under 40m each now.