It costs more to have an accurate, fast time-base sweep for an analog scope, so cheaper scopes generally have a slower maximum sweep rate.
Cost is not much of a factor for digital scopes since the physical horizontal sweep rate is unrelated to the displayed time base at small time/div display. The digital sampling system collects the data rapidly, stores it, and then displays it leisurely on the display. That's why high speed data can be displayed on a slow LCD screen.