We eat three meals a day, but sometimes you get hungry while resting at the room. Instead of grabbing an ice cream bar or other snack from the food court or park for a snack we get chips, crackers, grapes, cheese, juice, soda, beer and water from Goodings, which is at Crossroads. You could grab a cab or use the towncar service that allows a grocery stop before arriving at the resort.
The resorts with villas have lots of grocery items in their stores, but they are more expensive than Wal-Mart. However, you are saving money by not renting a car on the other hand.
You can always send a box UPS etc., to your resort filled with goodies a few days beforeyou arrive. When we went with my cousins, they shipped a bunch of baby food, snacks, disposable bibs and so on. It was not a problem-you just get the address from the resort and put your reservation number/confim. number on the address as well. Shipping water and soda is too costly, so that is a problem.
I do not know much about it but many people like the grocery delivery services. It is easier to get the water and soda and all other groceries from what I understand.
Someone on the boards could explain the grocery service more to you or use the search function. Good luck.
