I did all 3 for $5,000 8 years ago.
There really isn't that much material to learn if you are current and didn't dump everything you learned up to that point. The only thing new is flying from the right seat (takes a couple flights) and learning how to teach.
Before you can teach the material, you must know it. You already paid previous CFIs to teach you the stuff, so just study your old notes. Practice explaining stuff to the instructor before you get in the plane. If you can't do it on the ground, then there is no point of going in the air.