I know that this 'just value' is for January 1st of the year based on the transactions from the prior year. And this 'just value' is often not available until the following August.
How this 'just value' would compare from an appraisal for purchase and/or mortgage at the same date?
You can order two appraisals from different experienced appraiser and you will get two different appraised prices, so I understand that there would be variations. However, how accurate is the 'just value'? Is it on average equal, under or above the 'real' market value? Is each county the same or some are more often above, while other are more often below?
If you don't have access to good comp list or MLS, could you use the 'just value' as a proxy to run your first set of numbers to see if the property warrants more accurate research?