Traditional restaurants and/or fast casual spots in the USA involve “mandatory” tipping, so even if menu prices are lower, I would assume that the total meal price is higher once one includes the tip, which nowadays is up to at least 20% if not 25%. I remember a Facebook thread that drew some angry wait staff posting things like “You better tip X% or you’re going to get some nastiness in your food next time”, and they were mainly coming from low-end chains.