Please help! i want a nintendo dsi xl!?

i have a nintendo ds lite that i wanted to trade in for money for the xl but it turns out that i took the bar code off the nintendo ds lite so i cant turn it in. so far i only have $29 and dsi xl im going to buy is $169.99. please help! whenever i ask to do chores my mom always lets me do them for a week then she starts doing them. please help! best answer gets 10 points!