Compare options by price per unit and see which is the better deal.
Enter each option's price and its quantity (grams, ml, count, whatever as long as you use the same unit for every option). The tool divides price by quantity to get price-per-unit and highlights the cheapest.
A bigger pack is not always cheaper per unit. Comparing price-per-unit reveals the real best value, which is exactly what the small shelf labels show (when they bother).
Yes, add as many options as you like with the Add option button.