What points item should i get as Demo lock

So i have started leveling a warlock and wanted some advice on what item should i get from store with points.

Got 24 points atm and am playing Demo lock.

I would probably go with weapon, since getting a bis one is a hell of a challenge since it drops from Lich King himself on HC. In that case i would pick either Fusion Blade if you lack hit cap (and you probably do) or pick between Soulscribe or Fang of Oblivion. If you however are satisfied with the wepon you already posses, i would recommend going for wand: Scepter of Lost Souls. You could also pick Cosmos as your off hand or Comet's Trail as your trinket. It all depends on what gear you already have. Also remember this: When you level up you often get some sort of two hand staves as your wepon from quest rewards or drops. In 95% of cases its better to go with one hand wep + offhand. In that case i would consider buying a wepon and supplement it with some offhand that will you will replace as soon as you gather up points again or drop something valuable.