We walked away spending about $25 this year, thanks to stalking Office Depot for their sales. I changed up and bought good pencils this year, after witnessing our teacher last year having to throw away cheap pencils that won't sharpen. My kid got to keep his crayons, pencil box, eraser...mostly only pencils, tissues and ziplocs (for weed) went in the everybody pile.
I'm still in favor of just giving the teacher $20 at the beginning and she buys what she really needs. We have a brand new teacher and she is asking for books, because she hasn't had a change to build a library.