Everyone will most likely say go private and I would agree. With group lessons you stay at the level of the worst person in the group. It's more fun to learn with others, but if you want to learn at your own pace, go private. That way, if your really good, you will progress quickly rather than sit back and wait for the worst person in the group to catch on. Or conversely, if your awful, you aren't holding the others back. Lol
So in conclusion, if the cost isn't a problem, go with private.