Without knowing your "target audience" and how they will use the rifle, it is really difficult to GUESS which rifle caliber would sell best. Each of us has a preference but, are we going to be part of the auction process and possibly take the rifle home?
I'm assuming the two choices are what they are due to reamer availability and related costs.
For impulse buys, a 'boutique' cartridge of the moment like one of the Noslers would generate some interest and 'buzz' but, how many potential buyers want to add another caliber to their ammo locker? Reloading and on-line ammo purchases are a factor for many as well.
I get this is the LRH forum but, what is long-range to the prospective bidder? Are we talking ~600 yards at Pronghorn or ~150 yards at feral Hogs?