Even air...!!! If they could market it...they would. Hell this planet is called Earth (water planet) and we sell WATER to each other.
They sell air here in Pennsylvania.
I think it is illegal in some states, But if you pull up to most Convenience Mart type gas stations
you have to pay a quarter or more to put air in your tires
perhaps you must ask for a token or Refund if they are open I see this for Connecticut
Legally mandated free air for tires is not always Free ...