Ultimately, in a “free” market, all prices are basically set by auction. It might be hard to see that auction at work when you go to the store, but over time prices are really about people “bidding” a certain amount they are willing to pay, and producers deciding if that amount is enough. If a price is “too low,” than the people who are willing to pay more will “bid” up the price. If the price is “too high,” then the seller will have to lower the price.
So, with that said, just imagine an auction, that takes place every Friday, to set all the prices for everything. If I gave everyone in the auction a million “secret” dollars, then prices would go up automatically. I’d bid my normal dollar for a soda, but then the next person, having an extra million and wanting the soda, would bid 2 dollars, and so I’d bid three, and so on. Even if I only gave secret extra money to a few people, over a few Fridays the prices would slowly but surely go up, even without anyone revealing the secret.