The current MSRP for a White Lightening(despite the limited production it's still being made) is $2,669.99.
Sportsman's Warehouse lists 'em at $1,779.99 - $2,359.99. Currently on sale at $1599.97. Cabela's in Kansas City wants $1,399.99 for one. They're running about $1500 and up on Gunbroker with no bids on any of 'em. So you don't have a collector's piece.
A lot will depend on how fast you want to be rid of it. It might be an idea to talk to your local gun shop about it as a trade for something you do want. Or put it back in the safe.
Be advised:
"...businesses buying guns..." Base what they'll pay for a used gun, even a BNIB Citori WL, on their wholesale cost for a new one and how fast they think they can sell it.
"...the big book of gun values..." That'd be The Blue Book of Gun Values and it's ok for a ball park figure, but the Blue Book only give averages of prices from all over the U.S. with no consideration for local supply and demand.