The 10 luk on the tarnished lamp is the same kind of mistake as the autumn hairband. a bad idea they never bothered to fix and now they won't take it away because people got used to it.
I mean, yeesh. lucky shadow armor and wep is a two item set that needs a +9 refine which will run you $20~50 easily and only gives 6 total luk. this hat does 10 for no effort beyond obtaining it.
+10 LUK for free is good... make the game a little less P2W e-e