Cheap Wood Swing Sets

I am buying a wooden swing, but I am confused about what is a good type of wood to buy. ToysRUs has swings cheap and the same appearance as the CostCo / BJ's those who are almost double the price. Is it because of the type of wood? What type of wood should I be looking for a long life and low fragments?

pressure-treated pine.
It lasts very long in all weather conditions and low burst, not to mention it is very durable and relatively inexpensive wood ..

Menards, go tere