Ask HN: Consumer negotiation tactics - how do I avoid being taken advantage of?

I'm buying a house. I hear it's a good time to buy -- rates are low, tax incentives. Real estate and its agents are tricky.

I recently went into a nice new community being built that is essentially perfect, and I want to custom-build a house with the builder.

I was going to give them a call and start the process, but I forgot their business card. I remembered their names, so I googled them and found a blog post where they were mentioned as being star students of a very shady real estate sales course. -- http://newhomespecialists.blogspot.com/

It's tough going out there for consumers -- there's a lot of information asymmetry when negotiating the sale of a car, a house, or even medical treatment.

I was able to find plenty of sales strategies on how to trick and confuse potential customers, but what are some great counter-examples we as consumers can use to not get had?