Yellowstone National Park store prices

We planned our gas stops when we were near exits to the park. Still going to be more than normal but less than in the park. We bought basic groceries in the park. It's still cheaper than eating in the restaurants.

Your best option is on your previous stop, go to a regular grocery and stock up. Buying anything in the national parks is expensive. The town of West Yellowstone has a couple very small groceries that are a little cheaper than in the park if you get desperate. Maybe combining a grocery run one of your siteseeing days in that direction.

As stated, re-stock in Jackson when you get there. They have a couple big stores south of town.

West Yellowstone has more than one grocery store, so they compete. Also a good place for souvenirs and gasoline. Stop at the Grizzly and Wolf Discovery Center while in West Yellowstone. There's an admission fee, but its as close to a grizzly or wolf as you ever want to be. They test bear boxes from manufacturers using real bears. After seeing that, I wouldn't put anything in a bear box that I wanted back.

Two years ago, we paid $5.89 for a gallon of milk, bring everything you can with you. I always freeze and bring in a cooler and use it promptly.

It's been a couple years since we were in Yellowstone, so my memory is a bit hazy on that score, but that was only a couple years since we'd observed that fuel in Furnace Creek (Death Valley) was a couple dollars more per gallon that just outside the park. So we were prepared for things to be expensive.

But I do have to ask what possible incentive any store in Yellowstone would have to offer bargains? They are all concessions of the same company, so they don't compete with each other. If you don't like the price, feel free to drive to Jackson, or West Yellowstone, or someplace else to shop, as there are no nearby alternatives.

There's also some sort of yellowstone park tax/fee on top of everything. Also the store that's on the Montana side have no sales tax, while the stores on the Wyoming side do.

Everything inside the Park is expensive, there are no bargains. I would recommend eating out one night.
If you wait until you get to Jackson, shop at Smith's it's on the south end of the city. A great store, be sure to get a rewards card and save on grocery's and fuel.