Commercial property cannot be compared to residential. You buy based on the ROI numbers. (Return on Investment) Your purchasing this property to make money, if it does after costs, its worth what that number is. Assessments can be a guide, but usually not very accurate as far as market value. Assessment are based on the market when they are done, maybe 5 years between these times. In a declining market such as we have, you must wait for the next assessment to see it move down. Note: This makes no difference as the city can adjust the tax rate higher to create more revenue. So, next year your property is valued at 25K less. The city says, well the budject will be short,raise the tax RATE 2%. Now your paying the same thing.
Short answer, commercial should make enough money to cover short term coast increases.