Wow. This is strangely similar to my first experience. I was also 12, in 1984, and we were possibly the last people in our relatively affluent neighborhood not to already have either an IBM PC, an Apple ][ or a Commodore 64. My parents were German immigrants and extremely frugal, so I did not have high hopes walking into Computer Microsystems (RIP) on Northern Blvd. that day in Manhasset. But something about my interaction with, or reaction to, the Mac (which I had never seen before), the Lisa (which I had DEFINITELY never seen before), or the sales guy (Bruce Prevo, will never forget that name for whatever reason, RIP), must have convinced my parents to drop around $4.5K in 1984 dollars (that is $14,400 today) on a Macintosh 128k, an ImageWriter I, and an Apple 300 Baud Modem that day. The sum total of these was life-changing for me. (Not just for me... Supposedly, that sale is what clinched Bruce a free Porsche from Apple, which was the award for achieving the highest sales for some unknown period of time at the time. Bruce was SUPER charismatic!)
All I remember was being more blown away than I had ever been before or arguably since. I mean... this was so far beyond the green-on-black text-based UI's I was all too familiar with that I was just mindfucked. And I think that's what sold my folks on doing that crazy act.
A couple of years later they also started selling Amiga 500's. I was, for whatever reason, much less impressed.
Anyway, I spent much of the following summer coding in Microsoft BASIC for the Mac, which has its own backstory I only became aware of recently... tl;dr Cutthroat Microsoft tactics, as usual https://www.folklore.org/MacBasic.html