Another risk to buying something that has run up 30% in a year is the prospect of negative equity.

If you put 20% down, and the house goes back to where it was only a year ago (30% lower), you are in a negative equity position.  Meaning you will shell out cash to the bank if you sell the house (because the price will be below the amount of the mortgage).

This happened to my parents - they bought in 1988 and a few years later were in the position of having the value of the house fall below the amount of the mortgage.  They couldn't sell it because it meant finding an extra $100k to pay to the bank on top of the selling price of the house.

Keep that in mind when you buy something that runs this quick - it only has to "correct" to where it was a year or two ago and you will be locked into a bad situation.