my bathtub drainage is quite slow. I tried to run the snake through the overflow valve myself but to no avail. The snake won't go through very far. Since I have never done this, I did not want to force for fear to damage some mechanical. I called Abacus Plumbing. The guy was able to pull out some hair ball, but said the t-valve was broken. He said normally he could get this fixed pretty easily. However, he has no access. He proposed to go out to the backyard and pierce through a couple of bricks to make a hole to get his hand to in there to fix. His office quoted a price of $800. Is this a high price for Houston, Texas? I am shocked at this price, but then I never had this plumbing work done before, therefore, don't know whether this is the right price? Can someone give me some advices?