Marginal Costs & Marginal benefits in a choice you made.
Assume that I want to buy an ornament for hands. I spend $500 for purchasing an ornament. When I was supposed to see another I wish to buy that. But spending again for the ornaments also not a good idea. I am also not willing in spending $500 for the ornament. So, I decided to go for an ornament that costed only $250. No, my marginal benefit get decreased from $500 to $250. When I decided to go fro the second one or more than one of same good my marginal benefits decrease.
Marginal cost is something that changes in a smaller range in the production of one additional unit. For example I decide to manufacture 500 pens. i need raw materials for the production and a building and machine for production. The change in the cost or expenses that happens when I decide to produce 600 pens is the marginal cost.
