What about the use of SIMM Tree (or stacker or saver) that lets one plugs 2 or 4 matching SIMMs into one existing slot?  At one time I had a pair (left and right low profile, there was high profile for system that had 4 slots as the high profile could fit over low profile) for my Centris way back when memory was at a heart attack inducing $50 per MB and I was able to get a few 4MB sticks dirt cheap.  A few years later I sold those 4MB and the tree and got a 32MB SIMM for something like $30 new.

Dang I am old.  Today I could get 2 high performance 32GB (2x16) RAM for modern PC for that same $200 a single 4MB stick went new back in '93, and that's not factoring inflation.