There's also a Wal-Mart Supercenter on Sand Lake and John Young Parkway which is more on the way from the airport to the resorts if you're taking Hwy 528 to Hwy 4.
If you take 528, take the John Young parkway exit, go north a few miles and you're there.
Then go on Sand Lake (go west) and that takes you right onto Hwy 4.
I always stock up at Wal-Mart for groceries and it's a good place for cheap souvenirs too.