Yes it does, you need a complete service including water pump, all filters, and oils. Don't forget about the water/fuel seperator.
I don't work on Tohatsu but a yamaha, merc, or zuke would be somewhere between $350-$500 keep in mind this is for a complete service which is what you need for a 2008 even though you only have 50hrs.
It cost anywhere from $5,000 to $8,500.
Depending on which brand you choose to replace it with.
I'm only kidding. I have no idea. I know getting my Tohatsu serviced was a real mission. I know it was under $100. But that was just lower unit oil, new seals, motor oil, oil filter, and spark plugs. No water pump. I didn't own it long enough to require a water pump service.