Cancelling braces treatment after initial consultation and committment to go forward with treatment?

So, I had an consultation with the orthodontist my boyfriend recommended and after the consultation, I had my impressions made and I decided to go forward with the treatment. However, that particular orthodontist said my bite was fine and would only need minor tweaking. This kind of confused me because I've had clicking and grinding problems, so I decided to seek a second opinion and have since gone to another orthodontist who was much more thorough and addressed this problem and planned a treatment around it. I know I definitely jumped the gun with the first orthodontist (probably because the boyfriend went to him) and now I am really regretting having chosen him. I do not want to move forward with treatment. How much is it going to cost me to cancel my treatment with him, having already gotten the impressions done for the first fitting? Thank you and so sorry, this is so long!