Have the car inspected by a reputable shop. If the car has been maintained well and the price is right, it may be a great car. The Lexus is very similar to the Toyota Highlander which has proven to be a reliable car.
I bought my daughter a used 2001 Lexus RX300 in 2008 and it has been a great vehicle for her. They are very safe and dependable. We maintain it at our local Toyota dealership and save over the more expensive Lexus dealer prices. Timing belts should be replaced at 90,000, so check to see if it was done. A Lexus dealer can tell you you every service that was done on the vehicle since new. Only buy one that has a stellar service record. Check out the reviews this vehicle gets on edmunds.com site. No other vehicle I looked at got anywhere close to this type of positive reviews. Good luck.
I have enjoyed hers so much I just traded for a 2002 AWD RX300 this month. Love it!!