How much money would be left if i trade in my dsi to get a nintendo 3ds?

i have two questions 1.i want to go from my dsi to nintendo 3ds so im going to trade it in i have a stylus and a charger how much balance would be left over for me to spend 2.i lost my charger so i had to get a new one but the only one i could find was a multi charger thasat you had to put on adapters so you can plug it into ds lites dsi and gameboy would they still take that because they only take the dsi if you have a charger with it i will be trading it in at gamestop