Goodings is extraordinarily expensive. And I feel like they know they have somewhat of a "captive" audience, so they screw you. I'd probably take a taxi to a regular grocery store before I went to Goodings, just on principle alone.
If you are not going to have a car, consider using a shopping service, like wegoshop.com.
Someone has already given you directions to Winn Dixie...I have shopped there and it is fine. There is also a Publix on SR192, nearer to the Wide World of Sports side of WDW, which is also very nice.
Believe it or not, there are 2 Hess gas stations/mini marts on property (one near DTD and one near the BW) which are also reasonably well-stocked and pretty reasonable price-wise...more reasonable than Goodings.
Now granted, if you're looking to do full-course gourmet meals, you're not going to be buying the food at a Hess station, but if you are looking for breakfast, lunch and snack foods, they have a good variety, and probably also simple stuff like mac & cheese, spaghetti & sauce etc. You could feasibly take a Disney bus to DTD or to the BW and walk to the Hess staiton and then get back on the bus. If you're staying at SSR, the walk to the Hess station may not be too bad either.