Bart -
No, I also do not think you should request a price that is equal to what you paid for them ten years ago.
I agree that their value has gone up in ten years.
As a suggestion, try going to one of the gun auction sites such as
www.gunbroker.com and doing a search for the word "Luger" - this will give you lots of examples of various Lugers and what dollar amounts people are bidding on them, etc.
If you decided to list them yourself on an auction site, you can always decide upon a "Reserve Price" which is known only to you. And then if the reserve is not met in the bidding, the gun is not considered sold.
Hope it works out for you.