You can pick this up at market price for $21.93 but not much lower at the time of writing, as Lightning's value seems to be slowly spiking as well
However, this has delve and seven generic mana, so if you exile stuff from your graveyard as you cast this, this could be as cheap as a single mana
Its an all-round good card, and this gorgeous textured foil printing by Scott M
They achieve victory by depriving players of key pieces, slowly whittling down their resources, and often using their own cards against them
Or, you can take the traditional method by playing a bunch of value Elf creatures that can extend to the go-wide game plan
Granted, this all depends on your ability to keep the necromancer alive, as you're only able to turn fallen creatures into White Walkers so long as Draugr Necromancer is on the battlefield