I cannot tell you anything about the handgun, but I will say a few words about the caliber and ammunition.
.44-40 ammo is fairly hard to find in stores, and is usually expensive to buy when you finally find some. The price will be comparable to .44 Magnum ammunition, but the .44-40 does not begin to approach the .44 Mag's ballistic performance. The .44-40 uses a .427" diameter bullet, vs. the .429" bullets used in .44 Special and .44 Magnum ammunition, and the case has a slight taper; both of which combine to make reloading components and dies for this caliber less-common and more expensive. The sport of Cowboy Action Shooting has caused a resurgence of interest and use in the .44-40 and similar old-West calibers, otherwise prices for these cartridges would be REALLY high.
The caliber may be one reason that the price is so attractive, even if the gun is in great shape. It can be very hard to sell guns chambered in odd-ball/less-common/expensive calibers.