I believe the RCBS' Rock Chucker Supreme would be able to handle a .700 NE. You might have to do some unscrewing of the die each time to get the bullet started, but that would be a minor inconvenience compared to the money saved. RCBS' custom shop also makes a die set for it.
I think the hard part would be finding components for it. You don't pick up NE brass at the range.
On the other hand, if you can afford the rifle and the trip(s) its ownership implies, I guess $73 per round is a rounding error, so to speak.
"'Scuse me old chap. I just bought a couple of cases of .700. Care to have a go at plinking with me at my country estate?"