Is this where I would watch to see if there's going to be a group purchase? Or watch the forum that most-closely fits the product I want to purchase? Or both?

 

You need to read the sticky at the top of this forum for the rules.

Also, change the view setting options at the bottom of the page.
The default is '30 days' you can only see your thread because there has been no activity here for the last 30 days.

Change it to 'the beginning' then you can read how group purchases have worked in the past.