I'm not sure how to answer your poll.

In general, I think it's perfectly acceptable to charge more for private instruction than class instruction. I have no problem with that. But as Arik said, how much more I would be willing to pay, given your parameters, would be difficult to judge. 10% more? 15%? 20%? I don't know. Lots of variables to consider...my schedule, my finances, how badly I need the course, etc.

If you're looking for guidance, you might want to look at martial arts schools. Many schools and instructors offer both private and class instruction. You may want to find a school/instructor that's been successful for several years (implying that they don't have a problem attracting or keeping students with the fees they charge) and see how their fee structures work. You could probably find similar guidance with other types of schools...cooking and language schools/instructors come to mind.

ETA: I went ahead and voted "Yes," as I would be willing to pay more, but I can't say whether or not I actually would.