When will it need a timing belt and how much will it cost?

I would recommend replacing the front engine seals, timing belt tensioner, idlers and drive belts as well.

I'd replace the water pump, camshaft and crankshaft oil seals at that time. And yes, it's time for a new timing belt and water pump. Either of these items failing could be disastrous for the engine. If you want to find a Toyota specialist, here's our directory link for you: https://repairpal.com/toyota-repair-in-birmingham-alabama