I think this is waay to expensive....

Job description

Hi everyone. Thank you in advance for your opinions. I have a small leak inside of this property, and the leak it's l here somewhere. It only appeared after a very very heavy rain. In normal rain never had any problems. So obviously it's a very quick fix. I have been quoted £350 to fix this. I personally think it's way to expensive. Am I cheap, or the quote it's really out of this world.