I felt that the default Necromancer's Amulet was way underpowered due to the heavy Health and Stamina regen penalty; however, I also felt the other mods that tried to "fix" the amulet made it overpowered, so I made my own version. The new stats are as follows:

Magicka + 50
Conjuration spells cost 25% less
Health and Stamina regen penalty of 25% (as opposed to 75% before)