What is bottom line when negotiating?

A bottom line is the least you are willing to accept. You will not negotiate beyond that point. Car dealers use this in negotiations with buyers. But just because someone says "this is my bottom line" it doesn't mean it is a fair deal.

For example, a used car Kelley Blue Book is listed at $2300. A dealer is selling that model/year for $3500. He says his bottom line is $3000. But the customer knows the industry priced the worth at Excellent shape at $2300. The car at the dealer's is only in good condition. The customer counters with an offer of $1700 -- far less than the dealer's bottom line. The dealer won't budge. The customer calls his bluff and starts to walk out. The dealer stops him and says, for you, I'll sell it for 2400. The customer counters with $1800. Finally, they agree on the price of $1840.00.

Point: The supposed "bottom line" can drastically change---on both sides. A bottom line is not an absolute, but simply a suggested number or criteria.