While I generally agree with the opinions above, I have to say that sometimes the package deals are legit. As Pappy said, make sure that you know exactly what you're getting. (down to the model number) Remember that it's not a bargain if you don't need it. For example, if the package includes a post hole auger, and you can't imagine EVER using one. You get the picture.
Do your homework. Price the same model tractor on
TractorHouse. Call some dealers out of your area and ask for a price over the phone. Some won't give you one, but most will.
Then take the package ad to your local dealer and let him price it out to you. Tell him, up front, that you're looking at this package, but you'd rather buy from him. Most dealers will work with you rather than let a serious buyer walk out their door.
Oh, BTW, concerning service: Most dealers will work on the tractor, regardless of where it was bought. (they make good money doing that) In fact, warranty work cannot be denied. But, you may be way down on the priority list, behind customers that did buy from them.