In the US, the intro price for the 128D was $499, the Amiga 500 was $699. Though pricing was pretty volatile in that era.
My point is the C128D was available when the Amiga 500 wasn't.
The Amiga 1000, however, was out at approximately the same time. And it cost far more than a $200 jump. It must have been highly confusing for many that were trying to decide what to do.
"Should I go for the "3 computers in one" for less AND still have access to my C64 software? Or do I buy a computer "from the future" and start from scratch?"