Simplified Scenario:
Ore Brick:
1. OnActivate > Client > VCE_ModVariable (Wheat) [Add] (1)
*Player Harvests 10 Wheat*
Selling Booth:
1. OnActivate > Self > VCE_IfVariable (Wheat) [>=] (10) (2 4)
2. OnVariableTrue > Self > VCE_ModVariable (Wheat) [Subtract] (10)
3. OnVariableTrue > Self > VCE_ModVariable (Gold) [Add] (10)
4. OnVariableFalse > Client > ChatMsg > [You need at least 10 wheat to sell.]
After harvesting 10 wheat and then clicking the sell booth, it is saying: "You need at least 10 wheat to sell."