I believe that handle looking thing you refer to is a knee lever attached to the foot control that runs the machine. Light yellow, foreground. Under the bottom of the cabinet there should be a bracket that the foot control can be put in that allows you to operate the control with the handle looking thing against your knee.
I don't know anything about that machine model, and would assume it may be hard to find parts for. I know I maybe a cheap skate, but I think $50 is a bit high. I have received a few name brand machines for free.