I have not yet mboxed locks to be able to answer your question on a personal basis. However I do have several friends and guildmates that have done the quest and then gave the mats to someone else so that they could do it too. In theory you should be able to get the mats for one then do each toon individually. Once completed just swap the mats to the next in line. Yes if you have 5 locks it will be a pain but the savings in time and money spent on mats will be worth it.