A "certtified as genuine" 1719 Stradivari violin can (easily) be valued at more than one million dollars, depending on "condition" and the fame of the names in the so called chain of provenance.
A Stradivarius made in the 1680s or during Stradivari's Brescian period (1690-1700) could be worth several hundred thousand dollars or more at today's prices in auction. If made during Stradivari's...
It really depends on the model. The "Apollo" model is equivalent to student grade violins and those for the advancing student. They tend to be worth from a few hundred bucks to a thousand. However,...