Don't change it.
You won't get your money out of it from whoever buys it.
I had that same motor in my 98 Sienna. I did the timing belt job myself. Unless you've done timing belts in those Toyota V6s, it's going to be a fun job. Had to access bolts on the power steering pump and possible bolts that tend to snap on the center timing belt cover come to mind.
I changed my timing belt at 190,000 km back in 2010. All the lettering was worn off the belt, but I'm sure I could have gotten another 10-20,000 miles off that belt.