Shopping list and size

Have a shopping list option, where we can upload our shopping list and you can tell us which store will be the overall cost effective place to purchase from. Eg: shopping list(milk, eggs and bread) tesco will cost you at £5.80 Aldi -£4.80 therefore we recommend you should shop at Aldi today since it is better price value. Would be a 4 or 5 stars then. Can you not add Lidl to the price checking list too? Have a price sort by weight or millilitres not the whole price for the lowest. It can be cheaper by the size that way?