The explanation of mesh cost in the wiki has been updated. We still don’t have a real cost. But, how the cost will be determined is solidifying. See: Costs and Fees
There will be an as yet undetermined upload cost. It will be based on model complexity. Complexity will likely be some combination of triangle count for each LoD and Physics shape triangle count.
Prim Equivalence – Resource Cost
This is the item that is going to affect your tier cost. Cost will be based on the greater of these three items.
The shape and triangle count used for the physics shape determines the load placed on the server doing the physics calculations, which are mostly collisions. Physics is what keeps you from walking through walls. The Lab is promising more info on how this will work. See: physics weight
This is about how much data has to be sent to the viewer. See: streaming weight
This has to do with the number of communications that have to be sent to keep all avatars updated on the object. To Quote the Lindens: Server load from an object can be approximated by the number of messages that are generated from the object. The more object updates that a piece of content generates, the more data handling and processing the server has to do in order to keep all avatars in the area up to date with the object’s current status. When prims are linked together into a single object, there are some per-object messages that need to be handled, and some per-prim messages. Additionally, some pieces of content are far more likely to generate more messages – such as scripted or physical objects. See: server weight
We will have Avatar Render Cost (ARC) and Object Render Cost (ORC) once mesh is released. The effect of these items is mostly on the client side. If you have a complex avatar it can slow my render of the scene. This is not something the Lab is going to charge for or meter. However, the goal is to make this as low as possible with the imposition of the previous costs that will be charged.