I've seen some of the best pricing for used Kindles on Craigslist...and if you find one locally, you can check it out in person when buying. I occasionally see ones listed as cheap as $200 (some never opened).
Regarding ergonomics...for me the Kindle 1 was extremely ergonomic for reading no matter how you held it. The large key placement and easy to click functionality, made it problematic for some who would accidentally turn pages when not reading.
Oh and daffy-- I never go to "teaching the Kindle store" with my mother, we both decided that its easier for her to email any books she is interested in buying.
