An interesting feature of the Apple II was that it had three rows of sockets for RAM chips, each of which could take either 4k or 16k chips. That meant the minimum configuration was 4K (cheap) but it could be expanded in increments all the way up to 48K (enough to get useful work done).
Were any computers ever released that did the same trick with 16k vs 64k chips? I could imagine that being useful in the late seventies to early eighties, though it might be technically trickier due to some of the pins being used differently, as described in the answers to Can a 16K computer be upgraded to 64K?
To be clear, I'm talking about sockets on the main board, that could take either kind of RAM chip. There were certainly computers like the IBM PC that could take either kind by virtue of being able to take memory in expansion cards; that's a different thing.