Welcome to the LugerForums!
As the wise pipeman says, keep your eyes on the for sale section and you'll (eventually) find the gun for you at a reasonable and honest value.
My suggestion is that you make a book on Lugers your first purchase. Arm yourself with knowledge and then start looking. "Shooters" tend to run between $400 (if you're very lucky) to about $700 for a nice one. Above that you're going to get nicer shooters and low level (kinda) collectables.
(User results may vary, not valid in all states, viewer discretion is advised).
Good luck!