$120 is right about maxed out for the condition and the parts- that being said, you'd be hard pressed to buy anything new for that amount that would come close.

The parts are often found right in that grey area at the lower end of the market- right at the zenith of department stores and right at the floor of full fledged bike shops. With that in mind, "wheeler" bikes could be just about anybody, and you're probably not going to find much about the brand. I would imagine the frame is tig welded steel, most likely made in the same factory as lower end big name bicycles- trek, giant, specialized... In short, it's a good, but not great, bicycle.

You shouldn't have much trouble getting years of service out of this bike, just ride it.