Greed variation of Monopoly
Start the game with only $500 instead of $1250. To purchase properties, you can borrow money with interest to be paid back over a number of turns. The more turns to pay back, the higher the interest. How much you can borrow is determined by a scale. The first loan is $500. If you pay it back on time, you can go up the scale and borrow more. If you are late, you go down the scale and interest increases.
Ten turns, 5% interest. Twenty turns, 10%. Thirty turns, 20%.
A property must be purchased on every turn. If no one buys a property, everyone must take a loan for the highest interest/longest term.
You can mortgage a property, like traditional Monopoly, only it goes back into circulation if it is not un-mortgaged in 10 turns.