I may be too late to respond to this, but I'm currently taking the Kaplan course and here is my take on it.
First of all, I'm working full time and wanted to prepare for the GMAT. Now really knowing the timeline, I decided to go for the 10week plan instead of 4 week Kaplan course (same number of classes, difference in 2 times a week vs. once a week).
I paid 1350 for the full course and so far attended 5 classes. I enjoy the material and what they have to offer through online materials but I honestly think the Kaplan teachers are not helpful. Not only I find myself trying to get my teacher to explain better, I sometimes correct him with his method. I'm sure it'll be a different experience from teacher to teacher, but I was bit disappointed in what I get from the in-class session.
The true reason to take Kaplan was,
1. They offer High Score Guarantee program where you can retake it for free if you are not satisfied.
2. I just couldn't get myself to study after work sometimes. Having 1350 committed, if definitely reminds me what I need to be doing.
if you get yourself motivated to study and have more time, I would suggest doing it on your own.