It doesn't help that the flash manufacturers seem to be colluding on price and want to keep the cost of SSDs artificially high. Gotta make those margins! See recent DDR4 pricing issues for an example.

In the end it won't matter. 5 1/4" storage devices were always cheaper than their 3 1/2' counterparts, but a combination of factors, like how 7.2K, 10K and 15K RPM speeds were possible on a smaller platter, and seek times were faster due to shorter head travel, made the cost savings largely irrelevant.

The Quantum Bigfoot drive (https://en.wikipedia.org/wiki/Quantum_Bigfoot) was huge, storing way more than an equivalent 3 1/2" drive with the ridiculous amount of platter area, and cheap. The downside was it was relatively slow and noisy as all hell.

HDD technology won't go away overnight, but one day you'll wake up and chuckle about how things used to be. We had spinning rust in our computers! Hilarious!