Do not buy the boat with the OptiMax engine with 1,000-hours. That's too many engine hours, and I would avoid the OptiMax completely.
The Mercury OptiMax is a powerful engine, but it is a very complex design. Mercury
dropped the OptiMax from its recreational outboard line in 2018, about four years ago. Mercury service shops that are expert on the OptiMax are hard to find, and this will only become more difficult going ahead.
Unless you are certain there is a very knowledeable Mercury local dealership with expert technicians for the OptiMax, I would not buy a 19-year-old OptiMax with 1,000-hours.