Never Split the Difference is another good book to read.
Huh, didn't even notice. Thanks for pointing that out!
e.g. "I want 10,000" -> "I'll offer 5000" -> "Let's spilt the difference and say 7500" -> "How about 6000?" -> ... now you're already between 6000 and 7500.
"Okay, spliting the difference on that works out to 8000. Sounds good."