The cheapest way to tone a salt print would be selenium, followed by palladium. Palladium interests me enough that looked up kallitypes. A kallitype toned in palladium is pretty much the exact look I'm wanting from my prints. Due to the fact that I'm contact printing 4x5s right now instead of 8x10 or larger it would be interesting to do and not as costly as I thought.
I may do a little salt printing, but I think I'll also think harder about perhaps doing some kallitypes as well. I'm going to work on my negatives first, though. Gotta find a good way to get the film contrasty enough.