I had a contractor come to my house and do an estimate for a remodel job. He came back with a quote and I foolishly signed the quote. After he left I realized that he was significantly overcharging for the work. I received two additional estimates and also priced the material myself. I was right. The amount he wants is absolutely ridiculous. There has not been any money given to the contractor. The piece of paper I signed says Contractor's Invoice. It does not say Contract. There are not any terms on this such as start or end date. It is not itemized at all, just a total price of the job. Since there has not been any exchange of money and there is not a start date indicated is this a legal contract?