First of all let me welcome you to the forum 54rndball, as was mentioned above, you came to the right place for the information you are looking for. Another suggestion that should be of help as to what price you can expect to pay for a nice shooter or collectible Luger would be to check some of the major auction sites such as
www.rockislandauction.com or
www.jamesdjulia.com, once there you may have to create an account to access their prices realized for past auctions, I'm not sure about that. Then go to Auctions & Events, click on Past Auctions, then Search Catalog, type in Luger in Keyword, note any pistols that you may be interested in and note the Lot#'s, then click on Prices Realized and that will give you a pretty good idea of what the current prices are. Good luck in your search.
Lon