$30 dollars is more like it. Last year I had two old 4line kites converted to 5th line. Kite Magic in coogee did it for me. He added reinforced connection points, triple stiched the leading edge back together at the point where he opened it and sewed a ring into the webbing of my depower strap for the 5th line to slide through.
This for two kites and two bars all while I waited. took about 35min. total cost was 30 dollars. The guy is way to nice, he should probably charge more but I am not going to argue that point with him.