The Berean Bible Thumpers and Sola Scriptura
My own take on the Bereans is that they took to the scriptures "to see if it was so," not to extrapolate new doctrines that heretofore had never been held by the faith community. They were looking to see if the Old Testament scriptures supported what the apostles were preaching. Kind of like fact checking. That's a big difference from going to the bible to derive new and unusual doctrines by your own personal interpretation of scripture. For example, Ulrich Zwingli went through the New Testament to find verses supporting his new doctrine that the Eucharist was symbolic only, despite the fact that Luther was doing the same thing to support his belief in the Real Presence, which he later morphed into consubstantiation. Another example was Martin Luther stating that we are "saved by faith alone", despite the fact that scripture says specifically that "we are not saved by faith alone."
The Berean Christians did not come up with new doctrines based on their interpretation of the bible.
As Jimmy Akin said, they wanted to see if the scriptures really spoke of Christ the way the apostles were preaching it. The apostles through the revelation of the Holy Spirit and Jesus' wonderful exposition of scripture on the Way to Emmaus helped the foundling Church to understand that Christ was the Messiah as the Old Testament spoke of throughout. The Bereans, went to the scripture to see if it was as was preached to them. Since there were no New Testament Scriptures at the time of the Bereans, if you assume they were employing a solo scriptura mentality, they would have been locked forever theologically in the OT. This was not the case because the early Church relied on passing on teachings (sacred tradition) taught from the apostles, not just the Old Testament alone.
"Stand firm and hold to the traditions which you were taught by us, either by word of mouth or by letter" (2 Thess. 2:15).