I think once you get into the habit of it, it gets easier.
One or two portions at breakfast - a glass of OJ and some berries or chopped banana on cereal or baked beans on toast and a banana milkshake
Two or three at lunch: an apple, carrot, cucumber and pepper sticks
or a soup made from carrots, squash, leeks, red lentils etc.
Three veg at dinner: sweet potato, peas and broccoli or a pasta/chilli/chcken sauce made from some of these: onions, tomatoes, celery, carrots, mushrooms, peppers, kidney beans or lentils and frozen spinach or courgettes.
Snack on a pear, slices of melon or clementines.
It's not cheap but if veg is bought at the market or a budget supermarket like Lidl, is in season or reduced on its sell by date then it's affordable for most people.