Hey, I'm located in Houston, TX and actually test drove the 1998 you are debating buying. I would NOT buy the car, I repeat, I would NOT buy that car. It is a non-inspected Lexus for good reason. Once you turn it on, you will understand. Also, it looks like there has been body work done to the car. Did you notice how they didn't put any pictures of the engine compartment?
The only reason I liked the car was it was black on black and it had the Nav package. But to me, that's not worth buying a car that I know I will need to spend $$$$ on.
I ended up getting a 1994 with 47k miles and I'm very happy about it. Though it wasn't the color I wanted, nor did it have Nav, I know it will be a solid car.
Keep looking and good luck with your purchase.
-Reid