That's a pretty cool map actually... Didn't know it existed! Turns out I wasn't full of shit when I said I thought VT and NH had them.
No idea how much other racks compare in prices to their racks, but from the resorts point of view they can make money off the sale of the locks, and the racks are quite durable (they're just aluminium stock welded together, should last indefinitely.
Hope it works out for you! For what it's worth, I keep the key on a loop on the inside pocket of my jacket. That way I just open my jacket when I need to lock/unlock and pop it in my pocket.
Make sure there's no snow or ice in the slot where you put the lock in, I've heard of them getting stuck. Same with the pin, make sure it's not covered in ice.