Hi, Just joined yesterday after I saw your post. We just purchased our third Lexus yesterday-a 2006 RX400H for me. My husband is driving a 2003 GS300, and our daughter is driving a 1997 ES300. I looked a lot for our RX400h on every internet website I could find. I do think you might be a little too high by about $1000 to $1500.
I wish I could buy in some of the other areas in the US! Here in southern CA I found 2006 RX400h's anywhere from $38,000 to $29,000. The mileage also greatly varied. We wanted a 2006 with low miles and AWD. I did find one at the dealer in Mission Viejo-Bamboo Pearl with 19,000 miles for only $31,999 but it was 2WD. Beautiful car and a great price compared to all the other ads we found.
We finally went to an independent dealer so the car is not certified but it only had 17,700 miles and it's dark blue with AWD and has the Mark Levinson sound upgrade. We were able to get some money off and got the price down to $30,400 before taxes, etc. That seems thousands less than what many other dealers are offering.
We did see some private seller ads and they all seemed pretty close to the $30,000 mark. I would stay under $30,000 since the dealers can offer their certification. If we had found a private seller close to us with low mileage and AWD we would have been all over it if the price had been under that.
Good luck! I am so excited about my new car!