It's a toy, not a winning lottery ticket...
But you certainly don't have many options left. Really need to jump on these kinds of items when they're brand-new and not months later.
The easiest way, NOT the cheapest, is to purchase a set of Sound Gaia Memory R from eBay. Unless you get lucky and something is relisted, only the more expensive options ($70~ for the set) will be left. And if you're not interested in the other memories from the set... then a Double Driver is just cheaper. Bright side, you'd get Metal that way too.
Next best option? Go to one of our proxy services here. Between RiderProxy, Okinawam, and Yokatta, somebody's going to be able to get one from you. But it's going to be through Yahoo! Auctions Japan or somesuch, and that means you're looking at paying at least $20 for one after fees.
Last chance, and a long shot by now, is to hope somebody gets a SGMR case in the mail now and happens to have an extra Joker. Most everyone who ordered SGM1 or SGMR would have gotten it by now, but you never know for sure. I think those of us collecting the candy toy Memories have already moved on to preorders for the third set or at least the second.
As for you and Metal, DECADE453145, Vox Age is still selling one on this very forum. PM him.