If by "risk" you are asking whether there is a large chance prices will go down, the answer is yes. I would suggest you strongly consider alternatives before buying in this real estate bubble.
Although the realtors on this site will attack me for the following comment, in my opinion this would be a terrible time to buy, unless you must buy now (because of a 1031 exchange, for example). Inventory has increased, sales transaction volume has slowed dramatically, lending standards have tightened (pulling thousands of non-qualified buyers from the market), notices of defaults and foreclosures are increasing substantially, the economy is slowing (looking more and more like a recession) and literally thousands of high paying mortgage and other real estate related jobs have been lost in Southern California over the past year. All of these things will put downward pressure on pricing for some time to come.
The reality is that prices will almost certainly be lower next year, likely lower in 2009 and possibly even lower in 2010. Real estate cycles take many years to play out and we are at the very beginning of a down cycle. I disagree with many realtors who say that it does not matter what price you pay if you are looking to hold on for the property for 5 to 10 to 15 years. Let's say you buy now for $1,000,000 and prices drop 20% (actually, Forbes in a recent article estimated a 26% anticipated decrease from June '07 prices by 2010 for Los Angeles and Orange counties) over the next couple of years. You would have lost $200K in future equity by having not waited. Additionally, you would have to service the $200K by paying property taxes and interest on the $200K. Unlike a stock, when you buy at the wrong time, you need to service your hasty decision through increased property taxes and interest.
I have an MA in Economics from USC and have been in the real estate business for 15 years. In my opinion, this real estate bubble will take many years to play out. The previous down cycle was from 1990-1996 and values dropped approximately 20 - 25% in nominal pricing (40 - 45% in real numbers when factoring inflation). The 82 -85 down cycle was a bit shorter. However, that was a period of higher inflation which masked much of the decrease in real prices.
With cash in hand, time is your ally. Unlike stocks which are very subject to dramatic short term fluctuations, real estate is illiquid and cycles move slowly. If you are paying attention, you likely will not miss the change as prices tend to remain flat for an extended period flowing stability in the home market. Clues will be increasing transaction volume and a closer cost ratio in comparing the costs of renting versus owning. Simply stated, following a down cycle, people are generally more conservative in real estate purchases so prices will not likely rebound quickly.
Despite what the spin doctors at the NAR and realtors would like the public to believe â€“ it is NOT always a good time to buy.
With that said, if you have sufficient assets, you may not care about whether your home decreases substantially in value and there are benefits from home ownership. But, in my opinion, there are ample rental opportunities to wait out the deflating real estate bubble.
Best of luck, and if you want an objective opinion, don't waste your time listening to cheerleading realtors, who have a self interest in being overly optimistic about the real estate market.