Quoting a high price can give you a bad ruputation. I find honesty is the best policy, be diplomatic and tell them your not interested. I had to do a plumbing job in a basement a few years ago. The people had three large dogs that they didn't leave outside, they left them "go for a walk" in the basement it hadn't been cleaned out for years so you can imagine. I told them how unhealthy the entire situation was and I wouldn't go near it. They actually cleaned and sanatized the basement and called me back, I replumbed the house with new copper. It was one of the cleanest basements I ever worked in. I was surprised to ever hear from them again, but it worked out great.
talk about getting off topic, I thought this was a question about a basin wrench, I use the dremel tool works great, I would hate to see what happens to a ceremic or cultured marble top if that sawzall blade binds up. I would hate to replace a $200 or more top.