I only have two TI-83+'s. One I found in my house when I moved in, the other had a dead backup battery when I found it at a yard sale. Fixed it, and it works like a charm.
Those sound like great ways to acquire calculators!
I have an 83 Plus BE and an 84 Plus SE, and my brother has an 84 Plus BE that he doesn't let me touch. I use both of my calcs regularly for link program testing.