DuckDog

Bought a 1996 Lexus LS400 with 157k miles for $3,000. June 2014: drives fine but has power steering fluid and oil leak. Dealer recommends new rack and header gaskets for $5,000 cost. Indie shop bid is $1,000.

Is it worth it to repair?

Any alternative ideas?

Any ideas on how long the car will go if I blow off repair?

peterls

I think your post is miscategorized so not many people will see it.
Try to find out where the P/S leak is exactly. I have heard more than once that steering rack does not really leak on these cars unless you hit it with something. Usually the fluid leaks above it somewhere, and then drips or leaks all over the place and it is then hard to tell where the leak is coming from.
One of the cheaper fixes that worked for many was changing the seal between P/S reservoir and pump. Sometimes it is the low pressure hose, or at other times it is the high pressure P/S hose, or the notorious "idle air control valve" which would also tend to give you a bit of a smoke on start up. (however, my air control valve is also shot but it never gave me any smoke on start up - it just leaks and does not work)
None of those I listed are particularly expensive to do, you just want to make sure which one it is.
As for oil leak, it could be anything, and again - make sure you find a good mechanic who will find out where the leak is. Usually with your mileage, I would check the valve cover gaskets first. I did those myself, they are not too hard to do, just a little time consuming, especially on an older car like this where everything is brittle and baked on.