Do not buy prepper food. Buy and store food you eat. Assuming you are in the USA, you are not going to starve because the USA is a breadbasket.
What is going to happen is that because the US Government has declared economic war on its citizens, you need runway to win the war economically. You are being economically blockaded, so you will get through it the same way any war of attrition is won.
Keep a deep pantry. When you run out of something and you are at the store check the expiration date and compare that against the amount of that item you use in that timeframe, and then buy x amount of that item.
Learn to cook. This is absolutely paramount. Bulk calories are still very affordable but you need practice composing meals with them.
Buy food grade buckets, gamma seal lids, and oxygen absorbers. Flour for example; buy 25lb bags, freeze for 48 hours, fill into a five gallon bucket with oxygen absorbers and that flour can sit on a shelf for up to a decade. Between that and salt and a sourdough starter you can have years worth of fresh bread for a few hundred dollars. And critters can't spoil it.
Garden. Whether that is a backyard plot or a hydroponic indoor grow, you can insulate yourself from shortages and price spikes on perishable foods.
Buy meat in bulk. I buy whole beef primals and foodsaver them and freeze after breaking them down. I am currently paying $10 per pound for ribeye steaks, half the supermarket price. I haven't bought ground beef in years because I grind it myself.
Keep everything stocked up. Toothpaste, dishwasher detergent, laundry pods. Everything. Remember, this is an economic war, and food isn't the only thing you need to survive. You should never buy 1 of anything at the store.
This is all stuff you should be doing anyway. Do you know how freeing it is to run out of garbage bags, and I can just walk into my basement to get more?