So what you should ask is whether the estate price will rise within next 3 years and how much it will. If the cost of buying a house and selling it, plus the interest you would get and all other cost you can think of, is much lower than the 差价 you can earn, do it. It has nothing to do with whether you will stay in CA or not. But you'd better have enough money to pay all in once or installment within 3 years. Don't motagege(I don't know how to spell it.) Personally I think putting large percetage of your money in bank is the most stupid way. Money is used to make your life happier and make you earn more money. Of course no one can predict the market, but try to get more info.