I had a 1995 200 HP saltwater series. The last of the normally aspirated outboards. This engine had over 1,500 hours and was flawless. Yes, it sucked down the gas but it never gave me any pause and was easy to work on. Check the gaskets at the power head base for salt. This is a sign of the gasket failing.
Have it checked out and make sure the person doing the work understands how to compression test the engine. Hot and WOT vs cold with the throttle closed makes a big difference. If I remember correctly you want the numbers hot and WOT. Also, have the T-stats pulled this will tell you if the engine was flushed on a regular basis. I flushed mine after every use and had zero (0) salt deposits in the cooling passages.
Good luck.