Doesn't that assume that those local producers are only using local resources? It's very hard to be insulated well in this day and age. Livestock feed price is up. Fertilizer price is up. Equipment shipping costs are up, when they aren't hard to come by. (I can provide sources, but I just googled price of those over time and found charts supporting it easily enough).

Its very hard to be really insulated from higher fuel costs, even if it's produced locally. You still need to ship it to a refinery, and then ship it back out to gas stations. Unless you run a farm where you get all your inputs locally and they are also trying to use only local inputs, you're going to see these price increases. Many of the economic inputs people use for production, whether that be food or built items, have gone up, and often there's only so much they can do to insulate from that.