How much do you think this truck is worth?

It's a 2008 Ford F350 Super Duty with a Super Cab. 79,000 miles, hasn't been driven since late 2014. No visible dents or scratches but there's a very minor paint job near the front bumper. Live in Wisconsin so there's obviously undercarriage rust but not a lot. Interior is flawless. Standard bed size, 5 feet.

It was repossessed by my credit union a few days ago, they said they'll take 3 bids and highest gets the truck. I did some Kelly Blue Book research and it said a truck in that condition is worth anywhere from $15,000 to $20,000.

Anyone else wanna take a guess before I put my bid in? (Thinking $16,500 for a bid)

Since you have no idea of this trucks history or the issues it may have now, and one like this is around $16-18k with a limited warranty from places like Carmax, and this is an "AS IS" sale with no warranty, don't bid over $10k for this beast.
Also, this was strictly a work truck, likely driven hard and put away wet. No one pays for an F-350 when a cheaper F-150 would do.

Kbb.com

Offer wholesale value less $400.00

Seen one on autotrader with 33000+ miles and they were asking $24,900
So I'd guess about 22-23 Grand
But it also depends on what bells & whistles