Mine is about 533M right now. 100M is much too small unless you are purposedly not keeping parts of the basic minicpan.

I used to keep track of The Schwartz Factor, but that machine ran out of room on which to hold a CPAN mirror (although I can take the number from http://www.cpan.org/ now. Typically that number has been around 0.2. Today the full CPAN is about 2.8G, and my minicpan is about 533M, so that sounds right. :)