It really depends on what you like to do. All crafts can be cheaper or more expensive depending on what you do and how much time you are willing to spend gathering materials.
You'll have to learn a lot about how that works by yourself regardless of all the crafting guides out there.
A good (albeit slow) option for new players is the good old fishing+cooking career, there's good gil to be made there with very little investment (other than time) if you have the patience required for it (I certainly don't). Check out the guides here and in FFXIclopedia for more info.
