Wow, this is one of the reasons I also did my own product, as.. well, this
GameRunner device was announced at CES
2006... that's right.. 5 years ago! ...and it looked like it would never come.
$500 for it, which isn't all that bad. Only problem here is that it will probably weight a lot, which adds to shipping. Currently 4 months wait time... Anyway, I wish them all the best with it!
Again, I'm doing my thing for the experience, and the fun of it. Mine will also be cheaper for those that already have a treadmill.. and, my device works on other things as well. Such as stationary bikes. There are also extra pins (breakout pins from the AVR) which one can use to expand it's functionality. Such as simple buttons. Then it's just up to the software to do the rest (send the appropriate command over USB). I have a few "add-ons" in mind already. But really, adding a few extra buttons is quite easy, and super cheap (a few bucks at most). You really only need wire and the button itself... Besides, there is a lot of flexibility as how people can hook up and place the buttons!