I'd pass at 1K. Like others have said maybe $800, but IMO that's too much. I'd look at it as just buying the cab and the amp is thrown in for free.
The Carvin V3 head is pretty much a crap amp. A big fizzy, inarticulate non-versatile mess. I was really interested in this amp at one point and was close to getting one. I'm glad I came to my senses before I wasted my money. The amp almost takes away from the value of the cab if sold as a set.
Cab on the other hand, if it's plywood and not MDF would be a good purchase at the right price. If anything it's worth the value of the V30's.