Eating healthy can be expensive if you don't plan it well, but it's not hard to control costs if you stick to quality foods in reasonable portion sizes. Eating processed junk with cartoon characters on the box (which kids flock to) kills you. If you say no to that high fructose corn syrup trade-marked crap, you can keep things reasonable and healthy. We stick to organic things where we actually eat the exterior of the product (spinach, apples, etc.) and buy regular bananas and most proteins.
A garden is the best way to get quality food you can trust and you don't need much space. Potatoes, tomatoes, spinach, basil, okra and squash all do well in containers, but it takes practice. The main thing I've had to do is maximize sunlight in our shaded lot and fight off predators (bird, rabbits and squirrels). I've started making five-sided cubes covered in chicken wire as a way to keep out furry things.
