Even if you may have to move, there is almost always great financial incentive to buy a house vs. renting someplace. Every time you send in a rent check, you've pissed it down the drain - every time I pay my mortgage, it's like putting a bunch of money into savings. When I sell, I get an awful lot of it back.
Meanwhile, property values (If you pick your spot carefully) almost always go up.
They are currently building a very large restaraunt/retail/loft/movie theater type complex across the street from my loft. I expect to make roughly a $75,000-$80,000 profit on my place after 3 years total of living in it.
While Phruby is off base suggesting that you will always be poor if you buy multiples of plastic men (I've got thousands and am doing just freaking fine), he was absolutely correct in asserting that you're better off buying a place than renting - even if you end up selling it in a year or two.