Most listings are in the $30's per square foot per year. The El Paso de Robles region is experiencing a a rise in rates. In the last 3 months, the median rate increased $10 per sqft per year. That's a 38% increase in rent.
In the last 90 days, 14 listings have been listed, which means spaces most likley are going fast. You'll want to be prepared to make an offer immediately. About 7% of the listings in the El Paso de Robles are subleases, so you will probably need to consider the implications of signing a direct lease with the building. 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 600 sqft. Most buildings in this region are approximately 3 stories.