The price seems to be okay, but the frame is not a 58cm. More like 56cm from the photos.
Have you actually gone to see the bike, and try sitting on it to make sure that it fits?
Don't forget to pull the seatpost and inspect it for cracks. This type of Schwinn frame uses a "quill" type seatpost, and unfortunately, the ones used by Schwinn have a tendency to crack. Only one company make a replacement (American Beauty) and they are around $150 when you can find them.