Dear OP: I think we're pretty confused by the initial post. At least I know I'm
Shooter-grade Lugers seem more expensive in my neck of the woods than mapsjanhere's. That said, for $600, I would expect it to be complete and shootable with a halfway decent bore, but non-matching and probably ugly as sin. An older, poorly-done reblue would qualify. I would, however, expect it to be the real thing in an original chambering.
The original Luger cartridges were (a) 7.65
Parabellum aka .30 Luger or 7.65x21mm, or (b) 9mm Parabellum aka 9mm Luger, 9x19mm, or $9.47 at Wal-Mart.
Any other small caliber is a conversion. I've heard of .22LR Luger conversions, but I don't think I would touch one today.
The .22LR Ermas and Stoegers* are not Lugers, they are clever knockoffs designed to look and kinda
function like the real thing; they don't use a true locked-breech Borschardt-Luger toggle-link action, they're blowback, just with a toggle instead of a bolt. IMHO NO
Erma or Stoeger is worth $600 unless it's LNIB, and perhaps not even then; most of them fall in the $200-$300 range, and you can often pick up Exc to LNIB examples on GB for <$500.
*FOOTNOTE: I'm talking about the postwar .22LR pistols made in the USA by Stoeger, NOT the genuine Lugers made by DWM and imported by Stoeger in the 20s and 30s, often with an American Eagle chamber mark.