Well...let me take back what I said earlier. I do really love those two exercises (weighted dips and incline press), and I think those are all that's necessary for complete chest development.
BUT...there is no universal "correct" number of sets. The number of sets you should do is the most that you can do, without overtraining and without compromising training frequency.
That could be anywhere from 1 set to 10+ sets if you're strength training. It's not quite as black and white as "past this point is too much."