I know there are some mixed feelings about ATP; however my experience is all good. I got my commercial in a university setting and then went to ATP for my CFI about 2 years ago, and I have nothing but good things to say. I am employed by a university and all I have to say is study on your own and I did about 60 hours of ground training when I was at ATP. You will also learn a lot with you first few students. You can't beat about $5000 (price when I went, not sure about now) for all 3 CFI certificates, but I do agree it can probably be done cheaper.