There are literaly dozens of books in print on German WW2 daggers. Any of the bigger collector book dealers, or Amazon.com, can list oodles of authors and books, many who have current price guides. Fakes, replicas and copies abound, so be sure you can authenticate what you are selling tooget the best prices. Many of the manufactureres in Germany did not quit making daggers when the war was over, as they quickly found out the occupation troops were better customers than the Nazis! Those daggers are exact copies of the WW2 production, in most instances, but are copies never the less, not the original wartime articles. Small items affect value, like hangers, knots in the decorative silver wire, springs in the clips, tips on the scabbards, etc. Condition is the key to value, scarcity is next, and provable provnance is 3rd. However, if you have Hitler's personal dagger, it can be rusty but is still worth more than the winnning lottery ticket! I once bought a nice short sword type heavy dagger at an estate sale of a WW2 vet. It was gold plated with jewels in the hilt and scabbard, and a heavy silver hanger chain, obviously the former property of a top Nazi. Research proved it to have been Herman Goering's personal dagger! Turned out the GI had been in the unit that captured Goering's hunting lodge and he liberated the dagger and some of Herman's uniforms. The estate's executor had donated the vet's uniforms andclothing and the Goering uniforms to the local thrift shop, not realizing what they were.