Answer:
Irrational decision
Explanation:
Irrational decisions refer to those decisions which are not taken after enough deliberation, ignore the rationale, facts and logic, are rather decided out of whim and impulse and usually instantly decided.
In the given case, Joe was not willing to pay more than $500 cash yet eventually ended up paying $600. Even if the $25 gift card is considered, he ended up paying $575 which is more than he had decided to pay.
The choice of the consumer here is not rational or rather irrational since, he without considering other alternatives or exercise of judgement, without evaluating his costs, impulsively opted for the credit card lured by $25 gift card.
As per the economic theory, Joe's decision would be referred to as irrational.