Cool Hand Luke

I am the new owner of a 2008 194 FS (5.0 MPI Merc). Does anyone have any experience with those 12V oil changer pumps? They range in price from $20.00 to $120.00. If you do use them, which one? I would rather change the oil myself, than have to haul the boat back to dealership for every oil change. Thank you. Cool Hand Luke