I just bought the mysterious costume trunk twice, wanting to get the Brass Dragon Costume Trunk, but it hasn't shown up as an option to get.

Is it not avaliable anymore?

It's retired now :C

Oh, okay. Thanks anyway. [edit]Is there absolutely no way to obtain it then??

With the trunk?No But you can buy it C:

Okay, I'll have to start saving ;) Thanks again.

In the past they have "unretired" certain trunks, but it's rare, but still a chance if you save a MCT that you may get it in the future.