Why would a person already in an ESL class pay for a tutor ?
Classroom learning and individual learning with a tutor are both necessary parts of a solid learning experience.
While it is possible to do without one or the other and still achieve a workable grasp of the language, the most efficient and beneficial way is to include both.
It depends on the student's goals. If a student wishes to go on to post secondary education or job training, or be able to chat more easily with all their neighbours, a fluent understanding of everyday English as well as more specialized formal English is required. This is efficiently achieved with a qualified tutor. This teacher can design the learning situation to meet the individual's need both one to one and in a small group.
Limited ability in English equals limited job opportunity as well as narrowed social prospects. Sessions with a good tutor can be seen as an an investment in a successful future.
The session costs can be varied depending on lengths of time and numbers of students.