Cheap decking boards tend to be those that are built from pine or ash. This is because pine grows quickly and is a pretty standard wood. However, it needs to be treated nearly as quickly as you can get it laid down, as it is extremely susceptible to weather and termite infestations. This is because pine decking board is known as a soft wood. That is also the reason pine makes cheap decking boards, because it requires so much care and attention after you get it installed, and because it is plentiful.
For a more custom deck with a harder wood that does not require quite as much attention, you might want to consider cedar deck boards. Cedar is a great wood for decks because it is used to getting wet. While this does not mean you will not have to treat it to keep it looking nice, it does stand up better in the weather than your standard deck board. Because of this, it is also very expensive. Cedar must be harvested from swampy areas like Louisiana and Florida, which means loggers have to get into the swamps in dangerous areas to get this wood. That is why it is so expensive.
If you want a deck that looks like wood but does not require the maintenance of wood, then you might want to consider plastic deck boards. There are plastic deck boards that look and feel exactly like wood, but they are made from plastic. This creates the illusion of having wood without all of the extra cost and care. Plastic decking boards still require care in that they must be cleaned and taken care of, but you won’t have to worry about termites and other pests possibly ruining your deck, and it won’t warp in the rain and sun like wood will, which makes it superior to wood, if a bit more expensive.