By writing a command such as
~buy stone-carving 1 1 500 500 Ralabast (I know it says 1 in the top half of the pic, I messed it up and fixed it lol)
You can place a market order to buy or sell, check market for either, or what-have-you
To set it up, you download the bot, allow perms, and type
~market_set_channels <#buy> <#sell> <#bot-commands>
(You need to set up a channel for each of these)
By putting forth a buy sell, or purchase/sale confirmation, your order will reverberate throughout every server the bot is part of by cross-referencing a database and updating within the relevant channel.
My next step will be to set up a system where people can opt-in to be a courier to for a fee to help people move items.