I actually have a client that was burned 3 times. I did some cheap work for them b/c I was looking for work right after I finished a partnership with a friend.

I really didn't want to do work for them b/c they were cheap and distrustful after being burned so much but I needed the work at the moment. After 2 short assignments I had enough and I told them that I couldn't do more work but by this time they realized that I had delivered and they wanted to keep me, so I proposed a deal on balanced terms. Now I'm happy doing work for them, they trust me completely, and also getting a good deal.