KBB with VFRs is just about worthless. Point of reference: In '07, I bought a brand-new, zero-mile '04 model, with full warranty, from a dealer, for $6500; that's $500 *less* then a used '04 with average miles was worth, according to KBB. That was a non-ABS, no hard bags. I'd say ABS+bags should count for maybe a grand in your favor, but you're still talking about a four year old bike with no warranty as opposed to a brand new one... it might be low miles, but it's not new. $6800 is, IMO, unlikely. Near-identical bikes with higher miles can be had in the $4500-5 range; low miles aren't worth *that* much.
I know it's a tough pill to swallow, especially if they bought them new at MSRP. Good luck...