Sorry, but in reality you can't just write off all WalMarts as being "limited in what they stock". Limitations in stock vary from store to store. Our WalMart here in Culpeper nearly always has fennel bulbs - along with other "cook friendly" produce & other ingredients in stock. In fact, I'm more likely to find fennel at my local WalMart than I am at the other pricier grocers in town.
I'm also more likely to find a large variety of fresh peppers (Poblanos, Anaheims, Cubanelles), yucca, horseradish, daikon radish, dried peppers (at least half a dozen different types), eggroll/wonton/potsticker skins, lots of tofu selections, a larger variety of chicken & turkey parts - actually the list is endless as to what our local WalMart carries that other local markets don't. And at much better prices to boot.
Sorry, but my "cooking friendly" choices would be a lot poorer if not for our local WalMart.