Hoping this might be of use to some of you.
Found this linky while crawing the web and it has several listings for these you can check out.
I know hunting down a dewar that's priced right and of the size you want can be a hassle so I'm posting this as a resource you could use if you want. It compiles listings on Fleabay and it does make it easy to find these without having to sort through all else that may appear within a search for these.
It also has a list of what has sold recently so you can compare prices of how much a given sized dewar sold for within the last month or so.
This list is towards the bottom of the page below all the listings themselves.