When you buy bananas, they are the same price whether you buy one or ten. So it is ok to separate them. Celery is not like this. There are different prices for the bunch and for single stocks. Sometimes when I buy celery, I take off one or two stalks off the bunch and put them with the singles. I don't need the whole bunch, this way I get most of a bunch without having any left over and throwing it away. I feel guilty about this every time I do it.