I am currently enrolled in the Princeton Review LiveOnline GRE course.
I, like yourself, wanted to enroll in an in-person GRE prep course. Unfortunately, no one else on my campus shared my desire, and due to low enrollment, the in-person class was cancelled. I was not thrilled about taking an online course, but I decided to give it a chance.
I'm glad I did!
Students definitely have an opportunity to ask questions, whether through the use of a microphone, or by typing out a question. My instructor stops right away when she notices a question was asked. The teacher also 'calls on' students to answer questions, which I find to be very engaging. If you have a question while completing homework during the week, you can even e-mail your instructor.
The course teaches you awesome shortcuts and quick methods to getting the answers, and I have personally seen an improvement within my performance after a few weeks.
While it is pretty pricy, I would say that it is worth the money!