I hear people say this from time to time and I totally understand where they are coming from. I usually try to say something encouraging, but non-judgemental like, "It's hard, but it's totally worth it!"
But the real question is, "Is it too expensive?" Can you afford to eat unhealthily?
First there are the long term effects, like diabetes and heart disease. Then there's cancer on top of that. People who eat several servings of processed meat per week (hot dogs, lunch meat, sausage, pepperoni, etc.) have the highest incidence of colon cancer. Broccoli and other cruciferous vegetables like cauliflower and kale go a long way to preventing breast cancer. (This October, forgo the pink ribbons and go green- or white in the case of cauliflower. Actually, you can go yellow or purple as well since there are yellow and purple cauliflowers too. But I digress.) Monosodium glutamate is a food additive found in most processed foods (Top Ramen, Doritos, etc.) and fast foods (Kentucky Fried Chicken, Taco Bell, etc.) and has been shown to be a neurotoxin. Genetically modified foods have been linked to the rise in food allergies. At some point, we are all going to have to pay the piper. When we're faced with serious and debilitating health problems will "saving" money on groceries be a comfort? That's a question we all have to answer for ourselves.
But there are short term risks as well. I know this intimately because Malamute has Chronic Fatigue Syndrome, Rheumatoid Arthritis and multiple food sensitivities. We have noticed a very strong correlation between what he eats and how he feels, which in turn affects how productive and happy he is. Dairy, tomatoes, potatoes, corn, citrus, and commercial yeast have all been problems for him. When he has these foods, his energy drops and he becomes massively tired, depressed and irritable. Productivity and happiness go out the window. When I have flour that isn't freshly ground- even if it is whole wheat- I get crazy. I become more anxious and depressed than usual. You can't put a price on the happiness and the energy that come from eating well.
For us, we just make it a priority because there is no way we are going to survive as a family if we don't take care of ourselves. It's that crucial. And some how, the money has always been there for us to buy fresh, whole foods. It's like the law of tithing. The staple of my mom's cooking repertoire when I was growing up was hamburger and she said that we couldn't afford anything else. But you can get a bag of beans or lentils for a couple of dollars or a few pounds of sweet potatoes for a couple more and that will give you multiple meals and more nutritional value. It's fun when my dad comes by and samples some of my vegan cooking and likes it. But he was never too crazy about my mom's hamburger dishes to begin with either.
I've been reading a lot of success books lately and every one of them say, "Don't wait to be happy. Don't wait to pursue your goals and dreams. Do it now, because some day will never come otherwise." And that is how I feel about healthy eating. Don't wait for some day. Do it now. You can't afford not to.