Hi All I needed this feature
So I built it as a VM Joomla plugin as well as 1 change to the core unfortunately I could not see any way around it.
Any how it works like so
On the products detail tab, all shopper groups are listed in a new area, there is then an input box to add a specific price for each group, this uses the existing vm product_price table, so no changes to the DB are required. Hitting save then add the prices, removing the price from the input deletes the price.
When a user then logs with a shopper group which has a specific price attached, they are then shown the required price.
Any one interested please PM me, If there is enough demand Id ask the VM team to contact me, so the updated code could hopefully become core, it is only a small change which does have any knock on effects else where