How can i earn 500$-$750 in a month or 2?

Im gonna turn 16 in about a month and i have found a car that i REALLY want for $2k.The seller said the price is negotiable. If i get 1,500, im gonna see if he will sell it to me for that. i have about 800-1,000...not sure...plz help me b4 this car gets sold...oh, and no online stuff plz. thx. :)