How can you make a dollar out of 15 cents?

By bartering you can turn 15 cents into any amount of money, including a house, depending on the net value of the trades you make. I.e Buy a comic at a yard-sale for $0.15, sell the comic at an auction for $[n]. Alternatively, several deals can make you a dollar - sell a piece of $.15 candy for 25 cents, buy another $.15 candy and sell it again for 25 cents. Repeat. Now you have .30 cents profit. Buy 2 more candies, sell them, now you have 50 cents etc.

Finally, you can trade some paper clips ($0.15) for a pen, a pen for some paper, paper for some tape ($1.00) or what have you. With progressively strong deals - true story - you can end up with a house from a paper clip.