No- the 7x57 was developed separately, in 1892 by Paul Mauser. The 8mm Mauser (actually the 7.92 Mauser, but every calls it the 8mm) was developed by a government board.
Numerous commercial and custom makers have made 8mm Mauser rifles in the last 100 years
50-160 USD or so
What about it?
No
The 8mm Mauser is a good black bear round. American 8mm is kind of underpowered but with handloading or European ammo its in the same class as 30-06..
$450
Yes....
10000.00
"No, 7.92 is German military caliber for WW 2 and earlier Mauser rifles." Actually, 7.92x57 is the same thing as the 8MM Mauser, if that's what the person was asking.
7.92x57mm, better known as 8mm Mauser. Same caliber as the German military's Mausers.
100-1000 and up depending on specifics