I think number three, "Be Realistic", seems to be the thing people have the most issue with—especially when the market is rapidly changing (for better or worse). Just because you're car was worth $80,000 last month doesn't mean it's worth it this month. Sellers seem to think their mediocre car is worth top dollar, whereas buyers seem to think someone's concours level car is only worth the "poor condition" value. I have countless stories to support this… but I'd like to share two where being realistic is what ultimatley closed the deal.
1) When I was selling my 986 Porsche Boxster, it was in perfect mechanical condition—needed absolutely nothing. Body was excellent, no dents or other damage, but the paint, convertible top, and interior were all really tired (could have used a fresh coat of paint, new top, and reupholstered interior). At the time, really nice examples were selling around $16,000. I priced mine at a fair $8000. Lot's of lookers, but everyone who made an offer was stupid low, like $2000. I turned them all down. It took about four months, but I finally sold the car for $6000 when an actual enthusiast came to look at the car and noted a few things that even I had missed (and I'm very thorough). After talking about that, we agreed on the price—which we both felt was fair.
2) A few years after that I had a friend who had found a 986 Boxster that was listed at $20,000 from a private seller. This was fairly absurd as no 986 Boxster was selling for that much during that time. She told me everything she knew about the car and I gave her a lot of tips, things to look at, questions to ask, and of course told her about the IMS Bearing. Granted, the physical condition of the Boxster was showroom level perfect—exterior, top, and interior. But the seller didn't have any service records and knew nothing of the IMS Bearing. My friend went and drove it and asked all the questions I suggested, brought up the IMS Bearing, and explained she wouldn't be comfortable paying more than $10,000 for it given the completly unknown mechanical state (and yes, she took it in for a PPI and they said the same thing I did about the unknown things). Two days later the seller called my friend back and sold it to her for $10,000. He said it was because she brought up a lot of good points he didn't know about and she was the only one who looked at the car who really seemed the care about it. He went on to say how terrible he would have felt if he sold the car for twice that and then it failed on her.
In both examples, knowledge and being honest and polite (aka: not insulting) prevailed. In both cases both buyer and seller were happy with the outcome and felt good about the transaction. Always be honest and polite, do your research and (like the artilce says)… Be Realistic!