I started with my Commodore Vic 16 with a tape drive and then a Commodore 64.
I started with the DOS world with my Compaq portable running DOS 2.2
Here is a price list I found in my closet at home when I was cleaning up recently. I ended up buying this computer. Look at the prices!
$619 for a 80 MB hard drive. That ain't 80 gig that is 80 MB. It had a whopping 4MB of ram. The 2400 baud modem was the best part. It was WAY faster than the 300 baud I had been using. The 25 Mhz 386 was a screaming fast computer compared to the 4.77 machine it replaced.
If you notice there is no OS at all. I was going to use my DOS version that I already had.