buy game bundle already in library? (jc3 ps+ vs jc3 XL discounted)

I already own just cause 3 base game because it was in a ps+ last months...but I noticed that atm the whole XL bundle costs less than buying the single pass alone. So I'd like to buy the whole bundle (lower price and can keep the game if ps+ expires)..but my psstore says I cannot buy it. Any workaround?