How long have you been in the Kaplan course? When I took Kaplan, it took a while for my score to go up, but by the end of the course it had gone up 12 points. You probably won't get a 160 by the end of Kaplan, as I didn't and I don't think anyone else in my course did, either. But I didn't need to go and spend more money on another prep course as I just self-studied with good books like the Logic Games Bible and LSAT 180 and did as many practice tests as I could get. You made a mistake taking Kaplan; whether or not you want to spend more money is up to you.
I got my hands on a Powerscore Weekend Course book, and their techniques didn't seem to be radically different from Kaplan's (aside from Games, which, as I said, get the Logic Games Bible by Powerscore and you'll be fine there); the difference was mainly that they used all real questions while Kaplan only uses some, and that's probably where the biggest benefit is with them. Their RC stuff was of little help, and their LR stuff really wasn't anything I hadn't seen before. PR's techniques are also not radically different from Kaplan and are, in fact, closer to Kaplan's than any other prep course. I don't know about the Binary Solution, but I would stick with one of the main courses.
BTW, I raised my score over 20 points by the time I took my last practice test from my starting score.