Most listings are in the $30's per square foot per year. The Arcadia region is going through a a rise in rates. In the last 3 months, the median rate increased $2 per sqft per year. That's a 4% rise in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Arcadia region has more expensive rates, and you'll need to make a great offer to be in this hot submarket.
In the last 90 days, 5 listings have been made available, which means listings most likley are going fast. You'll want to be prepared to make an offer immediately. About 260% of the listings in the Arcadia are subleases, so you might be able to sign a shorter term by taking over a previous lease. 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 1,330 sqft. Most buildings in this market are around 2 floors. Most buildings in this region were built in 1984 and are Class B.