The conversion of a $300 Amazon gift card to Nigerian Naira depends on the current exchange rate. Exchange rates are constantly fluctuating due to various economic factors such as inflation, interest rates, and market demand.

To determine the exact amount in Naira, one would need to check the prevailing exchange rate at the time of conversion. Financial institutions, online currency exchange platforms, or even some banks can provide the most accurate and up-to-date exchange rate. For example, if the exchange rate is 1 dollar equals 410 Naira, then a $300 gift card would be worth 300 * 410 = 123,000 Naira.
However, it's important to note that when converting, there may be additional fees or spreads associated with the exchange process. These can vary depending on the method of conversion used. It's advisable to compare different options to ensure you get the best value for your conversion. Additionally, it's crucial to conduct the conversion through legitimate and regulated channels to avoid any potential fraud or issues.