The toggle switch on my beloved Blackburn Mars 2.0 has stopped working - truly a sad point in my life. I have LOVED this light for it's unique design, flash pattern and large size. If anyone knows of this light still being sold somewhere, please let me know! Most sites I've found that have them listed usually haven't realized that this model has been discontinued by Blackburn.
I agree with you about the Mars 2.0! Just looking at Amazon, they provide off-site links for a couple of vendors (don't know if those are the out-of-stock ones you mention). If you can't find the 2.0, the 3.0 isn't so bad.