When it comes to selling an Xbox Live gift card worth $300, there are several options to consider. One possible avenue is online marketplaces. These platforms allow you to list the gift card for sale and connect with potential buyers. You need to provide detailed information about the card, such as its denomination and any relevant codes or details. However, be cautious when using online marketplaces as there may be risks involved, like dealing with scammers. Make sure to follow the platform's guidelines and take necessary precautions to protect yourself.

Another option could be to ask friends or family if they are interested in purchasing the gift card. This can be a more straightforward and reliable way, especially if you know the people well. You can negotiate a fair price and have a more personal transaction. Just ensure that the terms are clearly understood by both parties to avoid any misunderstandings.

Some local gaming stores or pawn shops might also be interested in buying Xbox Live gift cards. It's worth checking with them to see if they are willing to offer a reasonable price for the $300 card. However, they may not always offer the full value, as they need to make a profit from the transaction. But it's still an option to explore if you want a relatively quick and easy sale.