Hi Niki, This is basically the same as buying Lost Mines of Phandelver (LMoP) in physical form, and then buying Shattered Obelisk in physical form at a later date. To my knowledge, Wizards of the Coast (WotC) doesn't give anyone a discount if they own the physical copy of LMoP when they go to buy Shattered Obelisk. It is also worth noting that Roll20 may not be able to offer special pricing unless their contract with Wizards of the Coast allows it. Most likely WotC controls the pricing structure for products sold on Roll20, either directly or via contractual limitations. Note: I am not a Roll20 staff member and have no knowledge of how Roll20 structures their deals with WotC, just offering a likely possibility.