Starvald-Demelain

Good evening Tenno, Had a quick question, I am attempting to acquire some mods that have been frustrating me for a while. Specifically some of the Orokin vault mods like critical delay. I decided I would purchase that mod from a player, and I am using the recommended market. My question is one of etiquette: When I copy the given text, I assume I am to whisper the seller in-game? Then is it customary for them to invite, or me to invite? Additionally, how is the trade performed, technically? I am not sure where I should be clicking to start trade, or select silver etc. Finally, is there a reputation/vouch system to post about the satisfactory trade? This community has been very nice so far, but I am scarred from several super negative interactions trading with players in Diablo 2 so I wanted to do my due diligence first. Thanks!