There are only two reasons I can see for booking a package--an extremely good discount or if you want the dining plan. Otherwise, it is NOT ever cheaper--still might not be cheaper with the dining plan.
If you don't want the dining plan and you purchase components separately, you save money.
Disney is the most expensive place to purchase tickets. And, everyone has to be on the same ticket. You can find help about learning how to purchase the right ticket(s)
HERE, which is a huge help to saving money.
Now, if you want the dining plan, look at it very, very carefully. Saving money isn't saving money if you wouldn't have spent that money in the first place. I'm not sure if that makes any sense, but plan your ideal dining plan and compare your overall costs of that v. what the dining plan would cost you--don't forget tips because if you are ordering more expensive meals to make the dining plan worthwhile, you will up your tip costs. My theory was developed from
HERE and the link within it.
Not related directly related to saving money, but cancellation and change fees, along with payment requirements are much more liberal/generous with a room only reservation too! Depending where you are staying, you may have to put down a bigger deposit, but you don't have to pay the total out as much and have more opportunities to adjust without penalty.
MouseSavers gives a great overview about if packages are right for you.
