I think I had 4 slots with 4x1MB so $400 would have been 4x4MB for 16MB. I made do for a few more years though, I didn't have anywhere near that much cash for "just" memory.

That 486/DX33 ended up being upgraded to a Cyrix 5x86/120 (?) and I think I went to 16MB at that point. Memory prices were cratering around this time (99?) so in the end I think that whole upgrade was cheaper than the 16MB would have been a few years earlier.