Follow the six steps below to perform this glitch.
1. Go to a shop 2. Buy an expensive item 3. Go to the 'Sell' option 4. Choose an item with high sell value 5. Go to 'Sell' but hold the Right Trigger 6. While holding the Right Trigger repeatedly tap the 'Sell' option *WARNING* When you let go of the Right Trigger you will sell the item regardless.