Your math is the same conclusion I came to. My current render time in poser is 3 minutes.  15000 images where each image takes 3 minutes to render = 31 days of rendering time.  If it were 1 minute it would be about 10 days. 

I was hoping to render out a decent quality 10 minute avi in about 8-10 hours.  I'm hoping that a basic render in VUE looks better than a medium render in poser. Do you see what I mean?