Problem is that it’s not consistent from program to program or state to state.
My eldest did dual enrollment, she took 16 classes which were all tuition free (for up to 13 units a semester) AND there was no cost to transfer those units to her private university (though hers only allowed 1 years worth of dual enrollment OR AP to transfer.) The in-state public’s would have taken them all at no cost. My middle took 4 courses at a local private university. We paid 25 dollars a class and again, didn’t cost us anything to transfer them to his private university of choice. They took all 4.