If the child will be using, and is expected to use, the laptop at school, then fine. Otherwise, yeah a desktop at home should suffice.
I remember junior year of hight school in computer lab. The first day, we all walked into Mrs. Wilson's class, sat down, and looked around for our individual 5 1/4" floppies.
As we all looked up at her with incomprehension on our faces, she proudly announced that we weren't getting floppies to use. The computers this year, she said, came with a 'hard drive' already built in.
I can't recall the exact capacity she said it had, but it was some saganesque, made up figure like 10 mega bites. We all oohed and aahed, wondering how even a room full of students could possibly hope to fill up such a monster...
God, I'm old.