Dear Monty: We recently sold our home. We were planning on using an agent we knew. He worked for one of the large companies in our city. He came and looked at our home and took many photos and notes. He also measured the house. We felt he was very thorough. A few days later, he returned with his analysis and gave us a comfortable range. We were ready to list with him, but my sister knew of another company she thought was reliable. She said we should always get two or three opinions. We got in touch, and they went through the same process as the agent we knew. But, when they returned with their analysis, their top end was $70,000 higher. We were skeptical but decided we were going to try it. They had a few showings right away, and then it went quiet. Two weeks went by, and another showing. This buyer bought the house and paid very near the asking price. It would have cost us almost $70,000 had we not listened to my sister. How often does something like this happen?…