Hello. 1991 was an interesting year for Sea Ray. Make sure that everything electrically works in the boat (gauges, lights, stereo, controls, etc.). For the 1991 model year, Sea Rays, especially the sport boats where your model falls, had electrical systems that were a proprietary design and were prone to failures. Shorts unable to be traced, items not working, etc. If everything works in that regard after 29 years, you should be fine electrically. They changed electrical design for the 1992 model year. Other than that, the 3.0 liter is a great little motor.
Pay close attention to the engine and outdrive. Your maintenance and repair history on the boat is your friend.
I had a 1991 200BR. It was a great boat and I never had one issue with it.
Good luck!