$2000 could be hard. C&R dealer, with dealer profit counted, is listing lower than that and it has been listed there quite a while. Yours has a holster, may carry more.... in general, it's not a good time to sell a Luger. Better keep it if you can.
http://www.am-firearms.com/m13-luger.html
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[Edit] Currently, if you have a TT30, TT33, SKS, Polytech, etc, it's good time to sell. Not Luger, especially a Luger from family inheritance.