On average, listings lease in the $10's per square foot per year. The National City submarket is seeing a decline in rates. In the last 3 months, the median rate fell $10 per sqft per year. That's a 39% decline in rent.
Compared to the rest of the San Diego market, the National City submarket has smaller rates, so you should have no trouble finding a great deal in this undervalued submarket.
In the last 90 days, 6 listings have been posted online, which means spaces are probably going fast. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
Even though the median size is 59,040 sqft, there are still 0 new listings below 2,000 sqft. Most properties in this market are around 1 floors. Most buildings in this area were built in 1974 and are Class B.