Mine is a 1993 SC400. If I drive somewhat normally, I can go a week on $70 in gas. I drive 45 miles each day for work round trip, then weekend driving. As far as repairs, only thing I've fixed so far is one new brake rotor in the back, it was about $30 for the part, put it on myself. My PS pump is leaking, and Lexus wants $475 for just the part (this is a common problem btw). I can rebuild mine for about $60 in parts, or get a rebuilt online for $2-300.
That's all I know right now.