This is going way OT but if you're looking for something to be machmir on a "better" hashgacha, I think it would be sauces.
Good point. A list should ideally categorize those products that are worth paying for a top notch hashgacha as well as the items that one is needlessly paying double the price or more and largely need no supervision such as flour, sugar, pasta, raw nuts, etc.
Perhaps a numbering system in order of sensitivity of the item to help the consumer make an informed choice and put some downward pressure on prices in the frum supermarkets.