If they'll do the wiring for $30, let them do it as long as they have a good reputation. I spent well over $90 in start up costs to do it myself, and frankly if I'd been smart I would have done the math and realized it would have been cheaper and safer to let a professional repairman do it.
That's mostly for the motor though; if it's the foot pedal, I'd just as soon replace the whole pedal due to the safety concerns with those old pedals. You can absolutely do the pedal for around $30; just go to
http://shop.sew-classic.com/Cord-Set...ers-SCE123.htm and buy the cord there and you should be good to go.