Most listings are in the $40's per square foot per year. The South Pasadena submarket is going through a an increase in rates. In the last 3 months, the median rate increased $13 per sqft per year. That's a 38% increase in rent.
Compared to the rest of the Metropolitan Los Angeles market, the South Pasadena submarket has greater rates, and you'll have to negotiate above asking rent to be in this hot region.
In the last 90 days, 3 listings have come on the market, which means listings are probably going fast. You'll want to be prepared to tour spaces as quick as possible. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 500 sqft. Most properties in this area are around 2 stories. Most buildings in this area were built in 1950 and are Class B.