500Mb, 800Mb, what is the point? I am going to upload all my skins anyway. one by one or all together, they will occupy the same space on the servers hard drive. They should remove the limit all together. After all they are moderating each upload and could very easily deny an upload of excessive size for whatever reason.
Shared textures among relative skins just like ED practices for their own skins would indeed be awesome. I wish someone would show us how if possible.