I would say that is fairly common, depending on what figure, textures, hair, clothing you are using. The thing about saving a pz3 file is it saves everything in the scene. Now, there is a pyton script, morph delete, if memory serves, that gets rid of a lot of unused information thus reducing the file size. Haven't tried it myself but from what I have read others have had pretty good luck with it.

I must remember to remember what it was I had to remember.