well i paid 4500 which includes booster cost and labor.
it was replaced with 2006 vitz brake booster.
it was done by my own mechanic..he is a true geek and expert mostly works on imported cars which normally others dont touch. he explained me what was the problem and i was very impressed with his knowledge.
guyz recommended by ser_gtr was also an expert nothing wrong with him but since both thought it was the same issue so i preferred my own man.
one thing more the car pickup is very good now and i don't hear that noise any more.. happy man now
Thanks to all of you..