Gil seller?

There's something of an oddity I've noticed with the MB on my server. There are certain sellers belonging to the same company that, without fail, will always have a particular type of item posted on the MB. The moment it's sold, it's almost instantly replaced, and if you put up your own listing, it's undercut within five minutes (drastically so if it's been over a day), no matter the time of day. It's nigh on impossible to sell any of said items if you do anything other than sit beside the summoning bell all day, to the point that despite being popular items overall, they have the only listing, I'm assuming because others have given up. I looked up said players several times over the past few days, and they are always on, and always gathering/ crafting. It was going on before I took a break in early March.

Could they be gil sellers? I initially thought it could be crafters looking to make a lot of money pre-SB, but as far as I can tell they don't do anything else, and judging by the time scale they'd have more money than they'd ever need.

If they are on 24/7, they may be botting, or have multiple people watching the account. Or they could be living extremely unhealthy lifestyles and no-lifing FFXIV aiming for 999,999,999 gil before SB comes out because some people have goals like that. Regardless, they are clearly playing the MB hardcore, whether or not it is legitimate or assisted would be the main issue.

Put together a concise report of your findings (try to keep it short and to the point) and send it in. If it ever gets looked into, they'll be able to keep an eye on them and see data you're not privy to.

Compile as much evidence as you can of their playing habits; if they're literally always crafting/gathering it's most likely either a bot or account sharer. If you're knowledgeable about what they're gathering, you can easily see if they're playing legitimately by just following them as gathering bots are extremely obvious. No real person can follow the exact same path and perform the exact same options all the time within the same amount of time.