[Thaumatology] Divination as the Core of Magic

[Varyon]

This is a very good example of making lemonade out of lemons. Ritual Path Magic may also be worth a look for a basis, as in that the Sense <Path> effect is indeed the cheapest.

EDIT:

Originally Posted by Fred Brackin

Maybe Tolkien too. There was a Necromancer in Sauron's recent aliases.

I don't think Sauron's guise as the Necromancer ever had any association with what's currently called necromancy. He was a relative non-entity - a mysterious, evil sorcerer who captured, tortured, and murdered Thorin's grandfather (Gandalf got the map and key from him while he was imprisoned and Gandalf was infiltrating and investigating the keep IIRC), and who was stated to have been driven out by the Istari after the events of The Hobbit. I don't think what powers he displayed in that form were ever mentioned - it's entirely possible he was indeed practicing classical necromancy, learning information by speaking with the dead.