Aside from the price, the main difference between Berkshire Hathaway Class A shares and Class B shares is that Class A shares can never be split, while Class B shares can. “Splitting” is a practice in which a company can take it’s currently issued stock and multiply it by X amount by issuing X shares for each 1 that’s outstanding. Think of it like slicing a pizza: you start with one pie worth $20, and after cutting it into 8 slices you still have $20 worth of pizza, but in smaller pieces. You can then buy and sell those smaller pieces independently instead of having to move a whole pie at a time. Class B shares allow investors with less money to still get their piece of the pie.
Berkshire Hathaway has split their Class B shares once - in January 2010 when they issued a 50-1 split, where each investor woke up with 50x the shares they fell asleep with, but worth the same total value. This split brought the price for one BRK.B share down from $3,286 to $76.
Some other differences between BRK Class A & B are:
Voting Rights: Class B shareholder has 1/10,000th of the voting rights of a Class A shareholder since each Class A share represents a larger piece of the Berkshire Hathaway pie (there are only 709,840 outstanding Class A shares, compared to 1.39B Class B shares).
Performance: BRK.A & B will not consistently have the same performance, because they will still have different market demand; if BRK.A increases in value by 5% next year, there’s no guarantee that BRK.B will grow at the same rate.
Read more about how dual-class companies work.