I seen many of these on ebay selling for new a little over $300 a couple years ago. I looked into getting one for an inflatable boat I had at the time. I wrote the seller and he said it can be used in saltwater. I never did get one though. Just go with one of these and be done... Tohatsu Outboard Motor 3.5hp 4-Stroke
A lot more money but at least you know you getting a great motor and won't have to worry when its time to crank her up and head in.