I know I surf the internet too much but someone will probably appreciate this. I know layline has a "tail end" page updated with left over cordage for sale but they rarely have a good selection.
This website (hyperlink below), is updated daily and is the best I've found. If you can't find the line you want here, they don't make it. Bottom line is learn how to navigate the page and never order custom length line again. I'm completely replacing my running rigging with all spectra double braids, and I'm only spending roughly $300 with shipping. Don't pass this up!
http://www.hallspars.com/Categories5.aspx?Category=26c8fc4e-9fe2-41a3-8df5-4f47b5290149
