Jun Yiwama

Can someone explain me all the aspects of prim equivalents/land impact? like, how many vertices/faces make a single prim equivalent and how to make sure your meshes would remain the same polycount as they were in the program you've modelled them? (for me it's blender) because for instance, I've uploaded a model that had 6k vertices in it and once i've exported it using collada and imported it into SL it was 12k polygons and 60 prims worth of land impact. From what i understand the problem lays in collada as it turns every quad face into two triangular faces i.e makking the polycount twice it's size, but i still don't get why its 60 prims.