checkout price based on qty

I have 3 prices I want to offer to my customers
1 bottle $89
2 bottles $129
3 bottlees $169

How do I get the shopping cart to populate the price based on the amount of bottles the customer purchases. when I add 2 bottles to my checkout it just adds $89 + $169 = $258. I would like for the cart to display $129. When I add 3 bottles it multiplies 169 X 3 = 507. I want the customer to pay $169. How can I configure this so that the percentages are taken off.

The price that you need to enter there is always the price per unit.
If you want 2 bottles to cost $129, then you need to put $64.50 and not $129.

Ok thank you that worked. I should have know that.