Similar model to the one above, do you have any other pictures of the front & rear?
Cleaning the rusty top is pretty simple and straight forward, just takes some time and elbow grease. As long as everything checks out, $80 is a good price. The price difference is basically the time and effort it will take to clean up the second, while the first looks pretty much ready to go. Your call on how much your time is worth.
Don't get caught up in analysis, find a saw you will be happy with at a price you are willing to pay and start making sawdust. It is too easy to continually second guess and end up not making a decision at all and so not do any woodworking.
BTW, it is more than 10 years old, not really a bad thing, just sayin'. Maybe the seller just doesn't know much about it.