When I got my first IBM PC in early 1982, IBM only offered single sided single density floppy drives with 160KB each.
But double sided drives were already available on the market. The only problem was that the PC BIOS and DOS didn't support the second side.
So I bought a PC with no floppy drives and picked up a couple of double sided drives at a local distributor for $300 each.
As I'd hoped, they worked fine as single sided drives too, so I was able to boot DOS. Then I got to work on supporting the other side.
It seemed a bit complicated to try to merge the two sides into a single FAT filesystem, so I wrote a TSR (Terminate and Stay Resident program) that mapped the other two sides onto additional drive letters.
That turned out to be surprisingly easy. So the four sides on my two floppy drives were A:, B:, C:, and D: drives.
Later I got an awesome Tallgrass 10MB hard drive for only $5000, and that became my E: drive.
Now I knew my storage problems were over: I would never run out of space with that thing!