Let me tell you this before you get asked. These are the questions that will be asked 1. Does the game save? 2. Can you post a photo of the back of the game? 3. Does it still have a save file. 4. Is it a genuine Pokemon LeafGreen?
5. Those are the questions that you will be asked just giving you a heads up:)
BTW- I Know the answer to most of those but it may help to put it in the description just a helpfull comment...