jan 1, 1946 - Selectron Tube
The selectron tube had a capacity of 256 to 4096 bits. The 4096-bit selectron was 10 inches long and 3 inches wide. Unfortunately, the memory storage device proved expensive and suffered from production problems, so it never became a success. It was invented by Jan A. Rajchman. I couldn't find the original price, but today, one would cost $29000.
Added to timeline:
Some early storage devices, to more up-to-date ones.