Toyota Repair: leak in power steering, power steering rack, toyota celica

Question
91 Toyota Celica has a leak in power steering.  Mechanic said that I needed to have the power steering pump replaced, so I paid $300 for part and labor to replace it.  Celica is still leaking fluid, now he tell me that I need to pay $800 for rack and pinion steering.  Is this mechanic taking advantage for me?  

Answer
Probably not taking advantage of you, he just misdiagnosed the problem but then again, maybe both were leaking but the mechanic did not realize the power steering rack was leaking because the pump is higher up and will leak down on to the rack so it can be hard to tell. Try to negotiate for a discount and a break on the labor since the original diagnosis did not fix the problem, good luck.