It looks like that particular model uses a knee lever, not a foot pedal. See the little hole in the lower right hand corner of the case? That's where the knee lever is inserted in order to run the machine. There should be a knee lever stored inside the upper part of the case.
For me $40 is a little pricey for this machine (assuming it has the knee lever). I got one very similar (including the knee lever) for $25 at a yard sale. However, this one is in a little better cosmetic condition than mine.
I would not pay $40 if it doesn't have a foot pedal or knee lever. Expect to pay $35 or more for a foot pedal or knee lever.