I have a build server with a PVP week at the end of wipe.  The issue I am faced with is that people make enormous bases out of wood (twig can be destroyed, wood, stone, metal, hqm cannot) - and do not bother upgrading them until the day of the PVP week.  So essentially, they do not have to grind at all the entire month because there is no need for materials.   I want to essentially force them to upgrade because theoretically the upkeep for wood is 4x the cost, stone 3x the cost, metal 2x the cost, hqm no additional cost to maintain the upkeep on.  There are seperate convars for duration and sizes, but none for building grades.  Can you help?

I looked into the code and don't see an easy way to do this. While the damage and heal events related to decay can be hooked and modified per decay entity, the actual tax calculation is just derived from the build cost of the entity.

There are no hooks related to tax calculations, but one thing that's possible for a plugin to do (without new hooks) would be to alter the repair target of each building block after it's placed, to point to a separate dummy item which has a different blueprint cost. That would have the byproduct of making the entity more expensive to repair, but that may be of little concern for a PvE server, and you could advertise it as a penalty of building with lower grades. After some testing, I realized this part is wrong since the build cost function is overriden for building blocks. However, the same idea can be applied just using a dummy construction grade with a different cost.

Thank you for looking into it.  I was afraid there was really no simple way to do this.  Thanks again!