I'm in Hunterdon too and I'm curious where you have your car serviced? I've have an 01 RX 300 with 74,000 on it.
I have only done oil changes, trans. fluid change, and brakes at Midas. Looking @ James Toyota for timing belt. Have 93K on 02 Rx 300.
I've used Fisher Autobody in Flemington for a lot of work on my car and I'm extremely satisfied. Unfortunately body work too and their very good. I will go to them for the timing belt when its due. James is definitely cheaper than a Lexus dealer but Fisher was signifianctly cheaper than James on the repairs I've had done. Airconditioning, full brake job, heating cooling issues and most recently the replacement of an exhaust gasket and air fuel sensor. They do oil changes etc too but I normally do that myself. Anyway, their worth a call unless you feel you must have the timing belt done by a dealer.