In Nigeria, the act of attempting to sell a $300 Google Play card comes with several aspects to consider.

Firstly, it's important to note that engaging in such transactions might be against the terms and conditions set by Google and local regulations. Google Play cards are designed for specific regional and intended uses. Selling them might disrupt the normal flow of digital services and potentially lead to security risks.
Secondly, there are often risks associated with unregulated card sales. There could be issues of fraud, where the card might be counterfeit or already redeemed. This can cause disappointment and financial losses for both the seller and the buyer.
Moreover, the digital economy depends on proper channels and compliance. By selling Google Play cards outside of the official framework, it can undermine the integrity of the digital marketplace in Nigeria. It's advisable to explore legal and legitimate ways to obtain and use digital services rather than relying on unregulated card sales.