Also depends somewhat on the size of the raft you get. While there is always someone that will say they do it, generally, I don't think you'll want to R2 a large raft, especially given that you're new to rafting. A small raft, then yeah, you might consider it.
Also consider that getting a frame and oars means you can go it alone if you want to, and be very maneuverable, powerful, etc on your own. For example, I have a wife and two kids. The kids don't provide much help paddling (but they enjoy it), and my wife is not all that strong either. So, with the frame and oars, I can take us all pretty much anywhere (float trip and class III) and be totally in control, even if they are paddling.