Well what stuff exactly do you need? I know it can be difficult but do you have access to fresh fruits/veggies? legumes? whole grains? If not, you can order some of the dried goods (legumes/whole grains) from Amazon. Fresh fruits/veggies may be a bigger issue.
If your local grocer carries fresh produce and meat and stuff you've got most of the healthy products you need. I agree with ordering the other products- and if they keep a while order in bulk
In my case, small town = farm stands, which means I can buy fresh veggies for very cheap. If you think ahead next year, you can try canning/freezing to up your stash of health foods. Otherwise, I go for online and bi-monthly stock up trips.
It's hard to answer your question without knowing what you want to get from the health food store. Let us know what you are looking for. I also live in a small town & the closest grocer is 20 minutes away. It takes planning ahead to avoid too many trips to town, but it's doable.
I have plenty of access to various specialty and health food stores. They're fun to shop in, and I there are a few staples that I will always buy. Mostly spices and ethnic foods though, not necessarily "healthy" foods.
Buuuut, I do 99% of my grocery shopping at Walmart. It's a 1-minute drive (10-minute walk) from my apartment, and I'm a poor college kid. Their produce and meat isn't top notch, I know, but it gets the job done for a good price. Quite frankly, I do not have the money to buy $4 tomatos, nor the time to go bargain hunting at the various farmer markets. In an ideal world, I would, but I happen to live in reality.
That said, you don't need to shop at fancy overpriced organic health food stores. If you can get produce staples and meats and whole grains...the basics, you're set. If there are a few specialty items you specifically want, most can be found online.