We have used Garden Grocer on several trips to Disney World. Their service is always impeccable and their website it easy to use. They checked to see that our order was placed, delivered and correct. We ordered 40 dollars or so worth of drinks, breakfast food and snacks. Perfect for our family of 5 and a 6 day trip!
I heard about Garden Grocer from my coworker who used it when she was last at Disney World. I decided to try it on my trip to Disney. Oh my, was that the smartest thing we did. It was a snap ordering the groceries, they were delivered on time, and when I chatted with Garden Grocer staff, they were very helpful. Will always use them for future trips.
Very easy to use, prices are a bit higher than I pay at my grocery store, but for the convenience of having it delivered right to you and even refrigerated until you arrive it is a no brainer...you can save money off by making your purchase a few weeks/months in advance...and clearly most people know well in advance that they are going on vacation. So it should be easy to plan ahead and save if you know about it!