How it works
Message the bot privately: /alert pricing. From then on, whenever anyone in the group says pricing, the bot sends you that message and a link to jump straight to it.
/alerts lists what you're watching; /unalert pricing or /unalert all stops it. You can watch several words.
Private by design
Alerts are set up in a private chat with the bot, never in the group, so what you watch is nobody's business but yours. Only members of the group can set them, and messages from anyone who has opted out are never forwarded.
The same word won't ping you more than once every 30 minutes.
For the whole group
Anyone in the group can also track a word for everyone: /monitor starts counting it across the group's whole history, and /monitorlist shows how often each one comes up.