A familiar conundrum these days isn't it? So basically:

A) Pre-order now (from BBTS or similar).
B) Pre-order from Amazon JP when available.
C) Wait and hope for cheaper Hasbro release.

Given that the likelihood of a Hasbro version is high (almost certain?) in a non-licensed product (contrast with MP cars so far), I am personally opting for the last choice. I also never saw a Soundwave at local TRU stores, despite making some attempts to track it down... in the end ordering online from TRU served well enough, and I might be banking on this again. For me there is also the potential from the Perth pre-order llamatron kindly organizes.

Even if I miss out on all this, recent history suggests that second runs are the go (from Takara anyway). I'd been trying to get my hands on MP-08 for (literally) years, and was extremely happy when the reissue happened. Yes I ended up paying a little more, but for the time that passed, it was OK.