The cheap Chinese Bolo Mausers are indeed available, although often mismatched and in poor shape.
A German commercial or military model is by far a better gun.
Nice ones seem to run about 500-600 and up. Way up.
These fired corrosive ammo, so check the chambers and barrels closely for pitting.
Also, the main springs, firing pin spring, and bolt retaining pin should be replaced before firing these guns. Failure to do so could cause a nasty accident, as only the springs and that retaining pin dissuade the bolt from flying back and hitting you.
They usually also need a mag spring as well.
The caliber is not .30 Luger, but is .30 Mauser.
This is NOT Tokarov ammo, but is sometimes confused with it.
.30 Mauser can be had through Sellier and Bellot, and a few other manufacturers, I believe.
The original 9mm Para Broomhandles were only made for a brief time in WW1, but many have since been rechambered to this much more available caliber.
I prefer 9mm, as it is easy, and common, but the .30 Mauser ammo is superior ballistically.
Stripper clips are available, will fit either caliber, and are a neccessity, as otherwise, the bolt slams home on your fingers when the follower is depressed.