Hi Jon, I found another problem on your code:
// start customer
$meta_boxes[] = array(
You can remove [], it just $meta_box.
On step value, can you please change to full value contains zero sign, 0.01 instead of 'step' => .01?
If you still get error, try to comment out some other Meta Box (I though is Groups), to check what meta boxes generate error 🙂