You can determine how long a price is valid by setting the shopping cart quote lifetime. For
example, if a shopper leaves a cart unattended for several days, the price of some items might
change. By default, the quote lifetime is set to thirty days.
To configure the quote lifetime:
1. On the Admin menu, select System > Configuration. Then in the panel on the left under Sales,
2. Click to expand the Shopping Cart section.
3. In the Quote Lifetime (days) field, enter the number of days that a quoted price remains valid.
4. When complete, click the Save Config button.