I'd say they are about the same cost wise, or eating healthy is cheaper. But as you said, it's in the time, and people are lazy as shit.
You can buy chicken or pork pretty damn cheap at the store. This past week I bought a 6 pack of pork chops that are 1/2 a pound each, for about $8. I then bought a bunch of bags of frozen broccoli for $2 a piece. I use a bag each night for myself and my wife. To prepare the meal takes about 10-15 minutes. The longest part is waiting for the water with the broccoli in it to come to a boil, which is about 5-7 minutes. Then I let it simmer for 5 minutes, and while that is happening, I cook the pork chops for 2 minutes on each side.
A full healthy meal consisting of proteins and greens cost me about $2.50 a person and 10-15 minutes of my time.
If I'm feeling like it, sometimes I make cheese sauce at the same time for the broccoli, which consists of a tbsp of butter, a splash of almond milk, and like 2 pinches of cheddar cheese. That probably adds like another dollar to the cost.