The price of a delivery is going to be proportional to the distance, not the cost of the food. The delivery is the same overhead whether it's three tacos or a five course gourmet dinner for eight people.
It really isn't these days. Ordering tacos down the street has the exact same extra costs as me ordering Burger King across town. Same "service fee", same delivery fee, driver isn't tipped more or less (just the expected % of your order).
Eh, I technically pay 0 in delivery fees due to uber one or whatever but the fees somehow pile up anyways…the menu price of an item somehow doubles or triples I kid you not by the time I check out.