The value of your Broomhandle will depend on the model. Is it a cone hammer, large ring, small ring? The large and small refer to the size of the hole in the hammer. A cone hammer does not have the hole. You also need to count the rings on the grip and let me know how many there are. They were also made in 7.63 or 9mm. Which do you have? What is the barrel length and magazine capacity?
Your gun is the Standard Pre-War commercial model of the Mauser Model 1896. It may have dealer markings on it like "Von Lengerke & Detmold". It was made in both calibers.
It is a semi-auto pistol with a fixed magazine and barrel lengths ot 3.9" or 5.5".
The values for a 9 mm caliber gun are:
excellent-$3250, very good-$2250, good-$1500, fair-$1000, poor-$700.
Values for the 7.63 caliber gun are:
excellent-$2500, very good-$1800, good-$1200, fair-$650, poor-$350.
I hope this helps you,
On the model that you have, the barrel length does not affect the value. It can have either the 5.5" or 3.9".
It is hard to say why the numbers are different. Some could have been added during a factory repair or a unit number may have been added. There is no way to trace these guns. There were so many different contracts with countries other than Germany and numbers may have been added after delivery. No one can be sure why it was done.
It translates to "Mauser weapons factory, Oberndorf", (Germany)
There is only 1 version with a value over $4000 and that is a Large Ring six shot. The rest, whether pre or post war are all under $4000. The values given are from the 2012 Standard Catalog of Firearms.
I gave you the values on a Pre-War Standard Model. If you find the right person looking to fill in a gap in their collection, you might get more, anything is possible, but it will be very hard to do. If a local dealer said $8000, I would grab it and run. You can compare your gun to what is expected from Rock Islands next auction. They are very accurate in their prices.