In SF Bay Area I often see Asian restaurants in the same plaza as an Asian grocery, so I imagine they have a deal with the grocery? (Or their distributors.)
It's true; businesses like to lower costs. Consumers do too.
ok, but the modern problem is businesses also like to make more money off shrinkflation. Businesses like to drive up the cost of competitors. They like to buy out their competition and now they like to buy their politicians and loopholes. They like to create the illusion of choice, even though they're packaging the same food. They like to delute labeling requirements and play word games with ingrediants.
A near-opposite strategy is when restaurants give you bigger entrees to justify higher prices. That has its downsides too.
It's true; businesses like to monopolize markets and thus raise prices. Consumers don't.