I agree with Janey in that I would do more research before dropping $50. Kind of guessing here, but I believe the plug in your picture attaches underneath the machine on the right hand side, and then the cord runs out the back right side of the case through a channel molded in the plastic. Examine the cord from the plug to the foot pedal and look for any breaks in the coating.
If you have a multimeter, or a battery powered continuity tester, you can test the foot pedal, might take some trial and error given that there are a few combinations of pin pairs to try to find which ones are the foot pedal. The probes from a continuity tester (ohmmeter setting on a multimeter) would be in two of the three holes in the machine-end plug, press the foot pedal and see if the continuity tester lights up (typically there's a battery and a small bulb, if you complete the circuit the bulb lights up; or on an ohmmeter a completed circuit would show zero resistance).
That's where I would start, see what you find.