I worked this out a while back: including all the fitteds, AIOs, flats, covers and materials for making my own (incl wipes), we've probably spent around $900. Though we don't use the flats anymore, including those we easily have enough for 5+ days of use.
We've been in cloth since around 1 week and only one kid so far, but hoping they'll last for another.
We use only a tiny bit of detergent and are only washing every two days at the moment. I use the dryer ocasionally if things haven't quite dried.

