Sadly the boating
world ,like the machine tool world is based on massive mark-ups on standard parts
A bearing supplier once,not that many years ago sourced me two 750mm od Timken bearings at list minus 70%!
No-one ever pays the list prices -except the little guy at the end of the chain
it pays every time to get the bearing no and go straight to a supplier .
Another point is ,that often other bearings configurations will work -we often see units with double row ball bearings later upgraded to rollers by OEMs
But the ball units still give long service
so its always workchecking the sizes and load ratings of such items