Only 15 bucks to fix my old Kindle! Why didn't I think of that? I definitely miss the old one, and wish I'd thought of doing this to start with. I wasn't really excited about the new Kindles (the move to touch screens everywhere has been a thing I've been unenthusiastic about, always...I was hesitant to move away from the G1 to a touchscreen Android phone, too). I just assumed I had to "uprade".
Yeah, the lack of responsiveness/feedback makes the touchscreen kindles especially frustrating - my page turning error rate was probably >10%, between accidental brushes, double turns, and other mishaps. Really got in the way of getting lost in the book. Plus, I love the tactile feedback of the buttons they used on the old ones.
If you want an old one, looks like good quality ones are going for ~$60-80 on Amazon, and it's pretty easy to sell a Kindle via the fulfilled by Amazon seller program - just set a price slightly below others offering Prime, ship off your Kindle and other old electronics, and they send you money when your stuff sells.
Amazon still sells used Kindle Keyboard 3Gs for reasonable prices, if you're ever tempted to go back.