This sounds like a good purchase. Be sure to try out the machine in the store before you buy it. They have electrical outlets. Plug it in, make sure the light comes on, run the foot pedal without thread to make sure the needle goes up and down. Look at the wiring and make sure it isn't all brittle and crumbly. Especially if the Goodwill allows you to return items (most will), that would be enough for me to take the machine home.
Those Montgomery Wards machines are not great machines -- they tend to be noisy; however, they make a great backup machine, good starter machine, good machine for the kids to start learning on, etc.