Even fast food places have salads/wraps healthier choices. These places like to tempt you with unhealthy things all the time but they often offer healthy choices, which are yours to make.
But like siefer said, there are also inexpensive options for whole, natural foods. Bananas are available for less than a dollar per pound pretty much year round, and they're great for you. Also check out Pick Your Own
to find a farm near you where you can pick your own fruit/vegetables. I picked some peaches and nectarines a few weeks ago for $1.50/lb, which is more expensive than what grocers pay for them wholesale, but actually cheaper than what the same grocers will sell them to you for. In $20 you can get 4-6 Carl's Jr. burgers, or 14 lbs of peaches. Which one's healthier?
1) eat real food - more vegetables, moderate meat, moderate fruits, less grains, less sugar, less vegetable oils.
2) exercise - moderate intensity cardio, sprinting, heavy lifting, dedicated stretching and mobility.
3) live - relax, de-stress, meditate.
Disclaimer: I'm not professionally qualified to make any formal recommendations. I've just done my homework and I'm my own guinea pig. All of my data, unless otherwise cited, comes from a sample size of n=1 (me).