Most listings are in the $50's per square foot per year. The Murrieta submarket is going through a a rise in rates. In the last 3 months, the median rate increased $28 per sqft per year. That's a 100% increase in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Murrieta submarket has more expensive rates, and you'll have to negotiate above asking rent to be in this hot submarket.
In the last 90 days, 13 listings have been made available, which means spaces are probably leasing quickly. You'll want to be prepared to tour spaces as quick as possible. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,650 sqft. Most buildings in this area are around 2 stories. Most buildings in this market were built in 2006 and are Class A.