I had very long hair for a long time (like past my waist) and just had a simple trim now and then. Cheap.
Then I moved to L.A., had to present the whole mover and shaker facade to get what I needed to get (money, institutional support, etc.) and got my very first REAL haircut, a layered dealie with attendant awapuhi whatsits and a diffuser for my hairdryer. It worked, anyway. I did like it.
Had that updated now and then in L.A., then didn't have my hair cut for a couple of years, the summer before last just got tired of it being so long, went to Cost Cutters, asked 'em to cut some off. Wanted it to go to about the bottom of my shoulderblades in the back. Was one of those slapstick "Oops it slants a little to the right Oops it slants a little to the left Oops..." and I got about 6 inches more cut off than I bargained for.
It also was just so flat. I'd gotten used to layers, makes things more interesting.
After that grew out to a decent length (my hair grows super fast, too), I went to a real place, got layers. Only go there once a year or so, but it's worth it. A good cut -- and it's fairly complicated -- does its job even as it grows out.