There's nothing wrong with an unsure cook measuring every ingredient and setting the kitchen timer for each phase of cooking. But following recipes to a tee can get expensive, especially when it comes to seafood. Take snapper, for instance; the tender and mild fish is common in fish taco recipes and costs about $25 a pound right now. Flounder, though, is just as great in a taco -- and is currently half the price. Restaurants change their menus all the time based on what they can get a good deal on; there's no reason you shouldn't, too. <a href="http://www.virginiaseafood.org/consumers/howto/substitution.htm" target="_blank">This handy chart</a> categorizes fish by texture and flavor, offering many options for each.