You've just reminded me of the BASIC Stamp, which lead me to find this interesting website comparing that to the Arduino head-to-head. The BASIC Stamp was weirdly expensive for what it was, but that's probably my post-Arduino post-Raspberry Pi bias:
> Getting to the “Hello World” of microcontroller projects, the blinking LED, on Arduino costs $32 compared to the $119 for a Basic Stamp. This is perhaps a little unfair because the Basic Stamp board contains a full bread-boarding space. A similar setup for Arduino would cost about $60, still a 2x savings (and can made cheaper if you want).
[snip]
> The standard Atmel AVR ATmega8 chip used on the Arduino board can be obtained for less than $4. The Basic Stamp must be obtained from Parallax and costs $50.
As a kid who once got a BASIC Stamp microcontroller and project kit, one super important thing to understand was that it came before Arduino brought the prices way down. It was reasonable for what it was at the time, ie a tool used for teachers that also happened to be sold to the public. I don't know how popular it was in industry
