It isn't worth it for cryptarch rep ... Not nearly.
The concept is, they don't want to devalue the time Y1 players spent getting all the exotics, but they want to enable people who didn't get them to do so a little faster.
You would be expected to buy the Y1 engram, unlock an item you have been covering (say, Plan C), then buy a Y2 version from the kiosk.
Whether reality and philosophy line up is another question, but fwiw ...