$12,000 to $13,000 would be a decent price, assuming all maintenace has been done on time. That's really low mileage for a 2001 so I expect it's in really good shape. If you can take it to a Lexus dealer they'll do a complete inspection for around $100. I think they do the same inspection they do when they take a car in trade so it's pretty good.
There were some ECU and other TSB's that needed to be done on that year's model. If they were done they should be in the Lexus computer system. I'd get that checked too.