On average, listings lease in the $20's per square foot per year. The El Paso de Robles submarket is going through a a rise in rates. In the last 3 months, the median rate increased $29 per sqft per year.
In the last 90 days, 14 listings have come on the market, which means spaces most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 43% of the available space in the El Paso de Robles 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 posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 800 sqft. Most buildings in this area are around 3 floors. Most buildings in this region were built in 2002 and are Class A.