TM Stock
Drywall screens and concrete worked on cheap King stones, but I'll let someone else donate their Shaptons to find out whether they work on the more expensive stuff.

CBN 8" crowned face grinding wheel: $140
Low speed Rikon grinder: $100
Grinding Rest: $2 worth of hardware and scrap?
DMT DuoSharp 10" C/XC: $102
Atoma: $64 (hence David's post title)