From what I've been told the timining belt is original to the car and I have approximately 165,000 miles on the car. What would be a good estimate for a replacement if I use a local mechanic?

If you use the right parts OEM. $900 high for local mechanic. $600 low local mechanic.

Thank you didn't realize they were that expensive. Just lost my job so since it is not giving me an immediate problem, I may wait.

It is a fairly easy job if you are mechanical, and Japanese kits are $250 online. They have everything you need. 10 hours if it is first time doing it. I did one on a sienna 3.0. Not hard.

Thanks for the advice and I will do my research. If I can find someone else that is willing to do the work, I will purchase the parts.

Make sure you get and replace all parts. Belt, idlers, tensioner, water pump, thermostat and cam shaft seals. 97% of the time failure of a belt is one of the other seized pulleys or gears issue. Many YouTube videos on this 3.0 liter Toyota engine timing belt replacement. I followed one and it was perfect.