On average, listings lease in the $20's per square foot per year. The Covina region is seeing a a rise in rates. In the last 3 months, the median rate went up $24 per sqft per year.
Compared to the rest of the Metropolitan Los Angeles market, the Covina region has smaller rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 10 listings have been posted online, which means new listings most likley are going fast. You'll want to be prepared to make an offer immediately. About 210% of the listings in the Covina are subleases, so you might be able to find a shorter term or below market rent. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
Even though the median size is 2,600 sqft, there are still 0 new availabilities below 2,000 sqft. Most buildings in this area are close to 2 stories. Most buildings in this area were built in 1981 and are Class B.