The percentage of homes bought with cash has shot up in many markets across the nation. Nearly a third of all homes purchased in Los Angeles during the first quarter of this year went for all cash, compared with just 7 percent in 2007. In Miami, 65 percent of homes sold were for cash deals, compared with 16 percent six years ago.

The prices on all-cash deals are also rising significantly. In Los Angeles, the median price on an all-cash home this year is about $351,000, compared with $230,000 in 2009. Over the same period, the median price over all increased to $410,000, up $85,000. In fact, last month, home prices in Southern California hit their highest level in the last five years.

All-cash buyers, typically investors eager to renovate and quickly resell or rent out homes, are making it more difficult for first-time buyers, who typically rely on mortgage loans that can take weeks or months to materialize. More California homes have been flipped in the last year than in any year since 2005.

And while Los Angeles may be a center of the frenzy, it is not an anomaly. Buyers in Boston are offering $100,000 more than the asking price or placing offers on homes they have spent only minutes in. In San Francisco, Miami and Phoenix, sellers are looking at dozens of offers within days of putting their home on the market, often accompanied by letters from would-be buyers professing their love for the property. New York City has seen similar drops in inventory, and prices have been rising steadily since 2009.