I remember not believing my friend when he said that the OS and the games were inside the computer and didn't need to be loaded up via a floppy disk. That was my first time seeing a hard drive.
First hard drive I bought for a PC was 20MB. I remember thinking how I would never fill it.
My very first hard drive was for an Apple //gs. It was the size of a shoebox and was a whopping 5 megabytes. I was an Egghead employee at the time and after my employee discount, it was something like $600-$700.