Well, it depends what you consider taking advantage.
I personally find that at certain studios, such as a chain studio, where I attend, there is some people taken advantage of. Especially with seniors. Many times the teachers will talk them and pressure them into buying big packages (at about 5 to 10K) only to have them discover (after they have paid) that their teacher is changing!
This has personally happened to me, and as a result, am going to break my contract and ask for a refund.
In addition, at this same studio, the professional teachers/owners have hired people with NO DANCE EXPERIENCE, whom their students are paying them nearly $100/hour. To me, this is unacceptable, and it's taking advantage of beginners who do not necessarily know how to recognize professional dancing.