I've seen them go much higher than that...have seen great looking, in great condition, but not NOS, DD Goldedge's go for $300 and $400, if you do a search for these DD's on Amazon, you see them hitting the $500.00 mark...the Ducks are a highly sought after collectible.

Did a quick search on Amazon, yup, $499.00:

Amazon.com: double duck straight razor