Locking gear is a favorite of mine and is quite apparent with a quick view of this blog. When you have a lot of locking gear, having things keyed alike is a good idea. It makes it easier to unlock any item in the event of an emergency. It also reduces the problems you might encounter when locking the gear in the first place. It may cost a little more to do, but you'll reap the benefits with easier play. I've found the cost varies from $3.99 to over $6.00 per lock. It all depends on what you're looking for. It is also best to keep at least two or three separate key rings stashed away in case you lose one set. Nothing is as big a turnoff as having to use bolt cutters or a hacksaw to get a boy out of his bonds. Well, unless he is in riveted shackles.