I'm working on a Gearing System.
Here's how it works currently:
If you don't have a specific title, you can't access the vendor.
However, if you don't have the specific title, you have access to the preview vendor.
I believe people call this "MultiVendor" not sure.
The preview vendor uses an ExendedCost so players can't buy anything.
The issue is that, if a player attempts to buy an item in the preview vendor, even if he does not fill the requirements to the ExtendedCost, he will still get the item. For free.
You can see all changes done here; They are all related to this!
Not sure what's wrong with the code.