Materials cost about $60 to $100, depending on how many chains you need and what type of hardware you buy, but enjoy the many years to come because it will be well worth the money.
Make sure all the hardware you buy is of high quality and grade 5 or higher and has a load capacity that is within the safe working load limit (WLL) for the load that you are installing. We used hardware and chains that are rated to hold up to 1,700 pounds (or 260 kilos) of load. If you want to find out how much load chain and hardware need to support, just add the weight of the entire swing assembly.