Before I start, I'll just say that I've never had any gemstone accessories or costumes, but feel like other players would like this.
Okay, so as you know the gemstone boxes' rotation has completed, and I guess Grey Havens is moving on to new prize boxes. However, instead of making them only able to appear in like the surprise prize box (the one that has random prize boxes from the past, I think that's what it's called) and becoming pretty much impossible to buy the accessories/costumes except from other players, why not make them available let's say the first few days of every month, I mean, like the respective months that the gems represent. Or last few days, or middle few days, or on Saturdays and Sundays of the month. I think this will be good for not only the players, but also for Grey Havens ($) xD
Just an idea!
I'd much prefer the gem boxes to be updated with the new accessories (tails for example), and then put into a "gem surprise box". Essentially, you get one of the 12 gem prize boxes. Introduce it as a standalone promo, but then add it into a list of "rotational events", much like how Hazardous Hardcore Mode and the slime casino rotate around. I'd make them supply depot exclusive after the initial promo.
From here, you could re-release certain other themed promos, such as the status themed promos (dazed, electric, blazing, vile, wicked, slumber, glacial), monster themed promos (gremlin, construct, katastrophe, slime, stranger), and perhaps gods promos (frenzy, storm, raging). Heck, you could have a "knight-themed" box with spritely, dangerous, hazardous, gourmet/confection, and plunge boxes! Have one or two of these surprise boxes be available at a time, and perhaps if more thematic boxes come around we can throw those up on the supply depot as well!
Having these "surprise" boxes be available year-round but for limited times allows more players to get their hands on their contents, and by making them essentially randomized it allows rare contents to remain rare, but slowly able to trickle back into the game economy.
Alternatively, we could introduce a new kind of token/rarity that is extremely rare and allows players to purchase said surprise boxes at any time from either a new NPC or Brinks. Have these tokens be an energy bundled bonus during these "event" periods, but also throw them up on featured auctions, show up as krogmo bribes, and be traded for via grim/primal/forge sparks from Brinks. These new cosmetic tokens would give players something to always look forward to, and allows them to get their hands on older promotional items by simply playing the game.