Ah but that was for a Mac. In the days before the internet as we know it you didn't have commodity RAM for workstations. You had to pay extra or risk voiding your warranty. Plus someone else was paying so why run the risk?
Sure the chips were commodity but the modules would have a different pinout. They would be advertised as better.t
Another problem was that the more memory you bought the more it cost per megabyte. A set of chips to fill the sockets with 128Mb would cost three times as much as a set of chips that filled the sockets to give 64Mb.
In the June 1998 MacWorld, you could order a 128 MB upgrade for your brand new PowerBook G3 for $389 [1]. Not cheap, but not that extravagant.
[1] https://archive.org/details/MacWorld_9806_June_1998/page/n13...