Even the 128k was reasonably successful commercially. Hundreds of thousands of units sold, which was quite good for the time. Inflation-adjusted, it cost quite a bit more than the Vision Pro. They sold the same model with very minor revisions (512, then 512e) into mid-1987.

The 1986 Macintosh Plus was a huge market success and it is only modestly different from the original. Even the SE and Classic didn't change things much.