Maximum Net Benefit 1

Now let's use these concepts to see how many burgers the consumer would buy each week. Suppose the price of a burger is $1.98.

• The first burger yields a benefit of $10, and the consumer must give up other goods worth $1.98 to him, for a clear net gain of $8.02 of benefits from the first burger. The consumer will rationally buy at least one burger.
• The second burger yields satisfaction worth $5 for a net gain of $3.02. It would be rational to buy at least two burgers.
• The third burger yields benefits of $2 in return for $1.98, a gain of two cents which is better than nothing. The rational consumer will buy at least three burgers.
• The fourth burger, however, yields only $1 worth of benefits, and still costs $2. So the purchase of the fourth burger would lose $0.98 -- and the consumer, if rational, will not buy a fourth burger.

We can conclude that, at a price of $2, the rational consumer will buy just three and no more burgers per week.