I have the opportunity to buy this model for $50, used, from a local guy. I am mainly a runner, but I would like something to go along side my running in order to help build muscle, as well as endurance. With that said, I don't know anything of the Weider 9645. I am just looking for the basic workout machine that I can get a good full body workout. Definitely want help in the chest and arms. Just need some reviews.