Don't forget PP/PPK in .22 ... My last restricted PP in .22, decent shape, sold for $800 in about 5 minutes. A PP in .380 didn't last quite that long at $850. They might have been a bit low.
In good condition, a prohibited .380 is $500+ and a prohibited .22 ... lucky to get it for $600. If they're minty in boxes etc., more. So add the cost of replacing the barrel, the months of delay and paperwork BS, and you have $800 as a starting point for the .380 and, since the .22 barrel is harder to make and nearly impossible to find, good luck finding a restricted .22 PP/PPK.
If it's made by Interarms, it is worth less to all the collectors. A German Walther PP or PPK or PPK/S in .380 commands a premium, prohibited or not, since there are a boatload of guys who still want one. The US made Interarms copies are not as durable, and there are better and worse ones due to fluctuating "QC". The Interarms MARKED but made in Germany pistols are still less desired by collectors, but I'll happily take all of them. Still high quality manufacture with better materials.
I have a (German) restricted PP in .22 to test next week, and then we'll see you on the EE.