This is normal. However, if you are dealing with nutty HR, they will use the numbers you give them to come up with an offer that in the end wont be much better

This is normal. However, if you are dealing with nutty HR, they will use the numbers you give them to come up with an offer that in the end wont be much better than the one you currently have. Watch out for "performance based" bonus schemes, variable pay numbers, and deductions. Make sure you negotiate on "in hand pay." Insist on better "in hand pay," that ways they end up negotiating on your terms.