O.K., maybe it’s true. i just did an mls of that zip code and it appears french valley is the canary in the coalmine. Tell your friend to go get his money back. There were over 300 lisings of resales between 400k and 500k in that zip code with a population of 22k. I had to break the search in two 50k chunks because 250 results is the max when searching, I have not seen that in temecula zip codes with more than twice the population, but this is 12 miles away, I can smell the blood already.
Here is what you should tell your buddy to do. Go look at this 2,873 sq ft house listed as a one year old former model at 360k, offer 320K and pay cash, no mortgage.
There were more I just grabbed one but if he is putting down 65% on 421k and wants to live in french valley he is in the ultimate pigginton position, an all cash buyer. That is of course if he can squeeze into a 2900 sq ft house.