More detail needed. With dining? Without? How many nights? Base MYW tickets or with parkhopping/no expiration etc. added on?
Just in the abstract, you can save from about $200 to $900 off what the various components of the package would cost you separately at rack rates by using the package. Check out mouseavers.com -- gives an example of an 8-night stay at the poly, where the savings is about $800.