The gift shop at the YC is a more upscale clothing and souvenier store. I do not remember any groceries at all. I don't even remember a cold case with sode, juice and milk. There may be one but if so it was well hidden.
Well, someone mentioned with the BC Villas being open now, they carry a few things, but didn't menion specifics. I know they carry donuts and chips and some other entemanns (sp?) snacks, or at least they did the last time we were there.
The store at the YC doesn't sell much, maybe a few sodas and such. If you're looking for staples, milk, bread, etc, you'll have to walk over to the BC store. They do have af ew of these items, but at premium prices. the milk is sold in half gallon sizes for $2.95 each.
When we stayed at the Beach Club a few years ago we were able to get 1/2 gallons of milk, OJ, prepackaged sandwich meats and cheese, bread,Hostess donuts and pastries, etc. at the Screen Door General Store on the Boardwalk. It would be easier to take the boat over and back from the Yacht Club. The boat launch is right near the store.
Now that the BCVs are open they've expanded the food offerings at the BC store to accomodate guests in the villas who have full kitchens....it's similar to the food offerings at the Screen Door.
I don't know about other items, but milk is exactly the same price at BC as at the Boardwalk. I also found BC to be more convenient for carrying milk back to the room.