I would like to setup group pricing where anyone that's registered can see the Group Pricing and place a pre-order.

I would like to have these capabilities:
- The ability to start a group purchase and indicate a processing date that occurs at least 1 month later.
- The ability for others to join in the group purchase and get a lower rate.
- As more users join in the group buy the price gets lower.
- Once the processing date arrives I would like to confirm each order and process accordingly.

Is this possible to set up or is their a module that does this already?

Thanks