Online lessons are billed at $1 per minute.
In-person lessons are an additional $15 for travel time and expenses.
ie. a half hour online lesson is $30 and a half hour in-person lesson is $45 ($30 + $15)

To accomodate households with multiple students, these familes are billed per time and NOT per student.
This is providing the students are taking lessons back to back (not at the same time - as this would be considered a group lesson which is subject to specific rate discounts).
A half hour in-person lesson is billed at $45, but two half hour lessons within the same household is not billed at $90 ($45x2).  
Instead, the family will only pay for the time the teacher is there.  They would be billed $75 for the two half hour lessons, no different than a regular 1 hour lesson.