And so there is the key. The accessories.
If I was to sell a 1919, an MG-34, or another semi-auto belt fed, the question of 'what comes with it' is a key to consider.
Gun alone, no tripod would be $7K.
Add in an IMA copy/clone tripod for $500, a real USGI or Wehrmacht tripod for $1500-2K.
Add in an AA leg/extension (if it exists for your tripod model) for another $600
Got a belt loader? They start at about $1000, if it's in good shape with the box/transit chest? $1500.
Belts? $50 each for the cloth ones, though sometimes that's even more.
A doppel-trommel? Add a grand or so.
A correct indirect fire sight? $1000 or more
How about a clinometer? $100, another 50 if it's got the leather case.
Spare barrel? Add $300
Spare parts for the action? Complete spare parts wallet? $400-1000
1919A6 'set' (flash hider cone, bipod, shoulder stock, carry handle) and you'll see another $800 or so.
Selling with ammo? Belted? Make it a buck a round in the belt.
Ammo cans?
AA Sight set?
Cleaning kit? Headspace tool? Timing gauge?
If I was to sell all the *stuff* with the gun, you'd be looking at a HUGE price-tag, but you'd also get a turn-key set.