Enthusiastic  promotion, affordable prices, desirable activities, popular teachers, and  friends all help attract applications.

KANES  suggest leaders pass on an all included  "not more than" price to enable higher payments if numbers are less first expected.  Differences in price are small for changes to larger group numbers.
 

To keep within budget customers can also rearrange other aspects of the plan to accommodate for different numbers. 

Advantages for smaller groups involve easier management, more flexibility, mobility and space.