Rondo has been clear and consistent from the start with two things. One is he wants to stay in Boston, the other is he is looking forward to being a FA. Those are actually contradictory desires. I don't think he is lying per se but I think he fully intends to test the market, which if he really just wanted to stay in Boston, he would do more like Tony Parker and just stay. I also think his perspective is going to change after suffering through a season on a bad team. He also says it is not about money but if it was not about money, and he really just wanted to stay, he would have extended already.
This is all very reasonable for Rondo to do. I don't think he is a bad guy, but I do think there is a high likelihood that he will not resign once he becomes a FA primarily because he will want to play for a better team or at least a team that will be good a lot sooner than the Celtics will be good.