Coconut milk is an emulsion of oil and water so instead of drinking a gallon of milk you can just have a couple of spoons of coconut oil that has been centrifuged as it retains all the vitamins and antioxydents and good stuff.
By far the cheapest way is to get it imported from Tropical Traditions. It's what I do and even with shipping it only comes to £60. Well worth it, in my opinion.