I don't know why these policies were made, lowering costs at the source is easier than than price control at the margin. Foods follow a long chain with many ha

I don't know why these policies were made, lowering costs at the source is easier than than price control at the margin. Foods follow a long chain with many hands; farm -> processor -> factories -> distributors -> retail; you want low retail prices and farm to be economically sustainable, moreover sometimes the link in the chain are the same entity sometime they are distinct companies. You could keep track of prices along the chain (we already do with VAT) and reimburse expenses along the chain to allow farms to sell at higher price without it affecting the final buyer. Or you could just lower the operating cost of farms by taking the major expenses* and subsidizing them. The first also is highly vulnerable to exploitation since many farms sell to huge corporations that can outplay them in the regulation game. * Which I guess are wages, taxes, fuel, and material (food/fertilizer).