The 512BB, as far as I've seen, is still in the old non-Hot Wheels boxes. I believe Kyosho is re-releasing them this year, so wait a bit and look for them in toy shows and conventions, as I've noticed the prices are much better at those places.
I picked up a Kyosho Ferrari 328 (broken base tho) for $50CAD, and the mint ones were only 60-70CAD! Usually these things AT LEAST sell for $80CAD.