Both. it really depends on your situation. if you want to play it on the go, you need a battery. if you want to play it at home, then the charger is for you.
Explain that to Jav, that buyer has Spongebob Yellow GBA. that goes for 9,999,999. Isn't that a bit much? GBA don't even go for that now. this is why for the higher points I'm trying to get that GBA.