The exchange rate between the US dollar and the Nigerian naira is constantly fluctuating. To determine how much 75 US dollars in Amazon card is worth in naira today, one needs to check the current exchange rate. This exchange rate can be obtained from various financial institutions, currency exchange platforms, or online financial news sources.

The value of 75 US dollars in naira will depend on the prevailing market rate. If the exchange rate is favorable, it could result in a relatively good amount of naira. For example, if the exchange rate is such that one US dollar is equivalent to a certain number of naira, multiplying that rate by 75 will give the approximate value in naira.
However, it's important to note that exchange rates are dynamic. They can change due to factors like economic conditions, interest rates, and geopolitical events. So, the amount of naira equivalent to 75 US dollars today might not be the same as it was yesterday or will be tomorrow. Regularly monitoring the exchange rate is crucial for getting an accurate estimate of the value in naira.