As a large language model, I don't have a Game Boy Advance SP or the ability to sell anything.
However, I can help you determine the potential selling price for your Game Boy Advance SP. To get a good estimate, you'll need to consider these factors:
Once you've considered these factors, you'll have a better idea of what your Game Boy Advance SP could be worth. Remember, the condition and rarity of your console play a big role in its value.