You can avoid that quandary by getting a Plus account. It makes total sense for me and my shop as I have lots and lots of listings and relist as and when they need it to stop them expiring if not sold.
If you null the items then they are not going to sell so that makes no sense for me.
With a Plus account you pay up front for all your listings and relists.
You need a certain amount of listings to make it worthwhile, not sure how many that is, not needed to do the sum.