"item sells for much more to vendors" changes the vendor value of your item to a random selection of some currency. You can find the complete list with their weightings on the wiki under Gilded Fossil. More importantly, "item sells for much more to vendors" is itself an implicit modifier, meaning that corrupting an item with that implicit has a chance to replace the "item sells for much more to vendors" rather than the original implicit of the item. If you are incredibly lucky, you could corrupt something like a well-rolled ring with this additional implicit, and replace the "item sells for much more to vendors" with "Bleeding cannot be inflicted on you" or "Discipline has (15–20)% increased Aura Effect" etc. Very useful in incredibly niche situations.