The Hasbro version was pretty common here... not sure about in America though.
I guess the JP version of Gen2 Optimus was the preferred one (they tend to do the better, more accurate colourings with Classics), because on ebay it seems that the JP version is quite rare - I could only find 5 listed, at prices of $60-165 (compared to about 50 Hasbro versions that only go up to about $40).