From what I understand Aura Blues are just like Blue Versions of TT, is the recent discovery what is limiting the supply to the US? If it is I wouldn't worry. Some asian shrimp farm is probably mass breeding them and they will be shipped over soon enough lol
The supply IS still somewhat limited.
There is also anecdotal evidence that the selection and breeding process to create the blue strain of caridina serrata (or perhaps some unknown factor in this color strain) has made the Aura Blue shrimp more sensitive and difficult to keep than other caridina serrata (like the Tangerine Tiger).