I sell a lot of one-of-a-kind items on my website and when something sells I need to delete the page. I don't want to create a redirect because I could eventually wind up with hundred's of obsolete pages. I recently became aware of 404's and pages showing up as crawl errors in Google. Because of pages I have deleted in the past, they show up as crawl errors. Is there a proper protocol or some kind of workaround for deleting pages so that they don't wind up as crawl errors/404's?