Juneau has a couple of nice stores that sell Russian goods, in particular nesting dolls and lacquered boxes. They had some very nice samples.
However, do you shop eBay? There are hundreds of matryoshka dolls available there, in all different quality ranges at very reasonable prices. Of course, you do need to be careful of the vendor, and look closely at the photos.
Over the years I have purchased everything from cheapie ones to extremely nice "art" pieces.
The unknown reason for all the jewelry stores in ports is actually simple: the cruise lines own the majority of them! I knew there was something suspicious when every line we've sailed really pushed the port jewelry stores--they make it sound like they are doing us a favor by pointing us in the right direction. If you don't believe me just spend some time talking to a true local---we did.
The souvenir shops that are close to the docks in Juneau are owned by the cruise lines. A local informed me of this on our last trip to Alaska. When you go further into town, the shops there are owned by local residents. This is probably true in Ketechikan and Skagway.