Currently only tested in Chrome & Firefox. This product is not officially released by Shapeways.
Step 1 | Drag this to your bookmarks bar or right-click and add to bookmarks.
Step 2 | Go to your Shapeways Product Inventory Page, and click the bookmark. You can add all products to a given material and/or change markup using a percentage of your base price...
or remove all products for a given material and/or set a flat markup.
Step 3 | This bookmarklet does NOT save your mark up. It simply fills out the text boxes or check/uncheck things for you. To save your markup, close thepop up, and use the "save" button in the corner. If you decide you don't want to save, then click the "cancel" button in the corner of the page.
Note: I'm not a real developer, just somebody who feels the pain of the community. This works on Chrome & Firefox. Not so much on IE. Haven't tested it on other browsers.