If you're going to buy one, buy it from someone who knows what they are selling you OR somebody who thinks guns are icky and just wants to get rid of it.
I would guess that WWI and pre war (WWII)commercials will be a better buy than WWII guns and likely better guns. 30 Luger probably cheaper to acquire than 9mm. I have a passing interest , they are beautifully built guns but am not willing to invest the time ,effort and money to know what I'm buying.
Don't buy a story without provenance.
ETA; for a shooter the Russian reworks are probably te best bet