FYI you can tag people with an "@" symbol - @phart010 Like that! That sends the person a notification that you've called to them.
As for cost to code, we do have some features in mind that I think the community will really love for commerce style stuff (ebay-like).
Frankly, what you've described would require a complete database of games to create the selection criteria you mentioned, and that's not something we're looking to do juuuuust yet. Potentially down the road.
For the short term, I don't see why we can't simply use a "WTB" list (see the BST forum) and carry on similarly to before where we can say "I have my list of wants over here". VGS has a very easy to use copy-paste-from-google-sheets feature that will let you manage your want list in a Google Sheet (great cuz now you're not tied to our platform, if we die tomorrow your data isn't lost, it's always in your hands) and just paste the updated list straight into your thread.