Timing Belt and Water Pump Replacement on 1999 Lexus LS400

I have a 1999 two owner Lexus LS 400 with 30K miles. The car has been great and free of any problems. All maintenance to date has been performed by the Lexus dealer. The dealer is suggesting I replace the timing belt and water pump on the car. This is an expensive fix. I'm possibly looking to sell the car later this year and I'm wondering if replacing the water pump and timing belt is a must right now in order to keep the car in tip top shape - or this is something that can wait?

Asked by for the 1999 Lexus LS400
yes and no is the answer. timing belt, water pump, idlers and tensioner is normally done at 90,000 miles.
however, your car is nearly 12 years old. if you gamble
with this and the belt breaks or loses a few teeth, you've lost an engine. it's your car and it's your money.
do you really feel THAT lucky??