Phrased that way, again, I do what is in my client's best interest.
We do what our client directs us to do. It is not our job to make the decisions for you, but to give you the knowledge for you to make the decision. If I thought the home was overpriced, I would tell you that and by how much so you could offer what you wanted to offer. If I thought it likely that a 90K offer would be accepted, I would advise you offer that much. But again, if you had to have the home, it was listed at $100k and my market analysis showed it to be worth 95K and would likely sell for 95K, I would advise you offer close to 95K.
Your motivation is everything, despite the fact that it sounds like an article from a magazine. We are here to do what is in your best interests. It is rarely in your best interests to overpay, but sometimes it is in your best interests to offer close to what it is worth, or more.
Case in point: I had a client I was working with for a very long time. She was OK waiting on things, so we had put in a few low offers on homes and negotiated hard to try and get them low despite the seller's market we had here this past spring/summer. This one home came on the market I knew she would like, so we saw it within an hour of it coming on. We were one of 4 parties that saw it in the first 2 hours. She loved it and HAD to have it. I knew it was priced just about on point, and knew there was another offer coming in, so we offered 5K OVER asking. She lost out on the home because all 4 parties offered on the home and someone offer 7K over asking.
So, in the cases where she did not have to have the home and it was in her best interests to try to get a deal (her desires) we did so, but when she had to have it, we put our efforts towards that goal.