Background Noise

We have video of an interview and there is a lot of background noise. I have tried reducing the noise on my program but it still is too noisy. The problem I have is if I put the noise reduction mode on high, the voices from the interview sound strange. There is also buses and motor bikes going past which is very distracting, along with people talking loudly in the cafe. The video is 25 minutes long. I would need to know how long it would take and how much it would cost to take out the noise from the background. It doesn't have to be completely gone but definitely muted or at a low sound.