But yeh, just consider why the tutoring comapnies are cheaper than private tutors. Your cost is being spread over 15 other people , and your help is being spread over 15 others. They have economies of scale, they can afford to have a lower price than a private tutor because they get alot more sales ( and why do they get more sales you ask? , because they have slightly cheaper/ same price as private tutors), and when a person sees a tutoring company with the exact same price ( or slightly less ) as a private tutor then they seem to go for the tutor company because they have written notes, but the fact of the matter is, in a subject like maths notes will do very little for you , a good private tutor with lots of knowledge and tips and tricks will get you further than a tutoring companies' notes anyday.
Tutoring companies are not personalised, your teacher wont know your name, its much more awkward to ask quesstions and harder to ask questions in general, you get no out of class hours support ( If I ever did/do get anyone , which is very unlikely now, I would have encouraged them to email me questions anytime ) you dont get this from tutoring companies. Also , expanding on the previous point about no flexiability, there is no room nfor you to ask questions from previous weeks stuff, each week is a new topic! , whereas a private tutor would usually be very flexiable and happy to go over anything at anytime.
So look at the "real" cost of these tutoring companies , are you really getting more than you would from a private tutor at the same price? I would think not.