In a pinch, I can get my Nutiva coconut oil at my local health food store. It costs more, but the store stays open late and I love the ladies in the Nutrition section who can answer any health-related question I have.
Normally, I buy coconut oil at Vitacost, where the shipping is low no matter how much I purchase, and I'm also able to order a few large containers of my favorite protein powder. I buy a few 54 oz certified organic extra virgin coconut oil containers and store the unopened ones in the fridge.
Another excellent brand is Tropical Traditions, where you can find coconut oil without the coconut scent (but you won't find me with that one - I LOVE the coconut smell). Their website is just about as much fun as browsing YouTube for beeswax-candle-making ideas... a few movies and you'll become the expert on coconut oil production.
Don't forget to read my blog that has uses for using coconut oil in cooking.