Apparently these silver vouchers are worth stuff? I keep piling them up and I really don't pay as much attention as I could. XD
Once you hit 99, you can activate a Records of Eminence:
Quests > Objectives > Tutorial > Basics > Exploring the Trove.
This will provide you with an NPC to store the Silver Vouchers with, as well as purchase more for 100,000 a pop (up to five purchased monthly). You will gain access to a new Records of Eminence sub menu:
Quests > Ojectives > Content > AMAN Trove (or something like that).
Do those easy quests for vouchers as well. Store them with the NPC.
When the time comes that you're ready to make money, look for a yell in town for someone wanting to buy Mars/Venus orbs. Send them a tell saying you have one and they will meet you at a BCNM battlfield entrance and invite you to their party. They pay you up front (Generally 3m for Mars and 5~6m for Venus, but price can vary; I wouldn't take less than 3m/Mars or 5/Venus). You then trade your orb to the BCNM battlefield and take yourself and the other player in. At this point you can ask if they want you to stay or you can leave (ONCE THEIR CHARACTER SHOWS UP IN THE BATTELFIELD; Don't disband or leave before they are inside).
They will then play kind of a gambling game where they can open chests for a noise, thud, or loud thud which determines quality of basically random-to-this-battlefield loot OR a chest can be a trap called a Mimic which basically is an instant kill for the party and causes you to need to homepoint. (It CAN be fought, but isn't worth trying really; cut your loss and move on if you get a mimic).
The reason they do this is for rare drops from Omen and Vagary as well as a few items exclusive to this battlefield worthmoney.
Hope this helps.
Oh, and you could just go in the battlefield by yourself and try for a rare drop, but if you're level 90 now and don't really have another good source of income, this is a nice thing to do each month. You get a free Mars orb each month from the RoE and then you can redo the Content RoE requirements monthly as well as buy 5 vouchers so after time it adds up.
Good luck and may the odds be ever in your favor.
Edit: Oh, and once you've used an orb once it stays in your inventory. Throw it away immediately once you've used it because it's useless once its cherry has been popped.