Student or Learner
Is it possible to say "one good" for "one product"? Doesn't it have to be "one goods"? This is a part of some writing, but I'm not sure.
ex) Opportunity cost occurs when we choose one good, service, or action over another. The next-best choice we give up is the opportunity cost The in-line skates are Anne's opportunity costof choosing the bike, and the basketball is Brian's opportunity cost of choosing the baseball cap.
I believe this was written by a native speaker:
Producer is anyone who makes or grows a good, or performs a service.
Consumer is anyone who buys a good or a service.
Opportunity Cost is the process of choosing one good or service over another. The item that you don’t pick is the opportunity cost.
Capitalism is a system where resources are voluntarily redirected to each whose ideas are better than the last, and whose products serve more needs; competition is the process by which these new products and ideas are discovered. At any one moment in time it might appear that wasteful production of similar goods is taking place, but when consumers choose one good over another they make it possible for the producer of the more valued good to continue production, and signal to others in the industry to step aside. With government-granted monopolies, resources are squandered and incompetence is rewarded.
by Theodore Phalan
I have never heard or seen 'one/a good'. It seems very unnatural to me.
I have seen 'a good' to mean a product, which took me by surprise. It was in the sort of context quoted by keannu,
However, the OneLook Dictionary search finds only one dictionary out of 33 which allows that it might be acceptable:
4. (countable, usually in plural) An item of merchandise.
so we might reasonably conclude that its use is non-standard and advise students to avoid it.
As I experienced, they don't seem to use a singular expression of goods, "Goods" sounds like a general idea.