I'm making a 2 handed warrior with necromancy and had a question about the mana cost.

I think that the dead thrall spell cost 1000 base to cast plus 50% reduction. I also believe that you get a 41% reduction if you have level 100 in conjuration.

If those facts are correct then what would be the cost of casting dead thrall. If any of those facts are wrong (which they may be) can anyone explain what the overall cost is. I don't want to put more points into my mana bar then I need since its only for this one spell.

I can't be for certain, but I think that my last Necro had a 15% reduction and it cost 280 to cast.

I won't have any enchanted gear to lower the cost so the only reductions I will have is the 50% perk plus i'll have conjuration at level 100