The biggest thing to remember is that numbers that end in 0 inevitably feel like temporary placeholders, guesstimates that you can easily be negotiated off of. But anything you throw out that sounds less rounded — say, $37,263 — feels like a figure that you came to as a result of thoughtful calculation. Such numbers feel serious and permanent to your counterpart, so use them to fortify your offers.
Excerpt from: Never Split the Difference: Negotiating as if Your Life Depended on It by Chris Voss and Tahl Raz