I too am a teacher/SAHM turned tutor, I tutor mostly high school math but have done just about everything. Here's what I tell people considering coming to me.
If what your child needs is drill work, like multiplication tables, spelling, or lots of fractions or grammar practice, then the big centers are the place. They have lots of resources so the child won't get (as) bored with the stuff.
Most of the time though, children have "missed something" (for my students, it is algebra basics). This is where one-on-one is important, a teacher with 3 or 4 students all working on different, set topics is not going to be able to spot what the student is having difficulty with.
As others have also mentioned, a private tutor is frequently LESS expensive than the big centers, and some will even come to you!
As an aside, I've never figured out WHY someone would work for them, they pay only $10-$15 an hour in our area. I charge $30 and don't have to leave home.
