India has 4x the population, less land, and far worse technology and infrastructure than the United States. Shouldn't food cost in the US be less expensive? I've never been to India, but it seems like food costs far less there from what I see on TV (10 cents a meal). Why is this?
I think your intuition is right that food is cheap there. The Economist Big Mac price index suggests that India has some of the cheapest big macs in the world. More generally, the index indicates that there is a strong relationship between GDP per capita (a proxy for labor costs) and Big Mac prices:
Labor is a significant part of the costs of making food (25-35 percent in America). Transportation is a significant part of the cost of food grown far away (world bank data indicates that even exports fees alone can be substantial). But when food is grown locally and prepared locally, the total costs are significantly determined by local labor costs. In addtion, Indian restaurants probably also serves much smaller portions than in rich countries, particularly the United States. They may also make use of less expensive ingredients generally, more stables and seasonal vegetables and less dairy and meat.