.. You guys on this site REALLY count use a chat-site system to help give people a better way to let others know about their offers they wish to buy/or sell.
Can you provide an example of what you're looking for? We already have a inbox conversation system which you can convert to a chat and you can receive email and push notifications for.
We intend to add a direct chat but based on what you're saying you want us to add a global chat we have no plans to do this nor does any site in this industry. It's filled with spammers and potential scammers. The global chat hasn't worked out well for really any sites in our personal experience.