On the TB, Lexus says 90k or 6 years. You don't want it to go on your 96, it's got the interferance engine. If it snaps you'll need a lot more than another belt. At the least I would have it inspected.
I got a mint '96 LS400 with 112k for $7k down here in Florida, so I would keep looking for a newer / lower mileage LS. A little more $ could get you a lot more if you can swing it.
But....
New timing belt, water pump, belt tensioner and seals is a good sign of proper maintenance. Check the...
Hey FatCat! I'm down here in Miami too with my 96 LS400. I originally had my LS taken to the dealer for a pre-purchase inspection and was referred to LexAuto by the dealer themseleves. Great Lexus mechanic that has done my Timing belt, water pump, seals, complete tune-up and strut rods...
If you're really considering this car, you might want to consider taking a Lexus delaer for an inspection that way you know where you're at. I did, it cost me $150. But the small things they found gave me a lot of leverage on the final price.
I've got a 96 myself. You are going to be due for...