With an average of 2 Mb for skin, you have about 10000 skins...impressive!
Quote from another thread:
The one thing I am most proud of though, is my skins collection; [The Skinventory], started in 1997 (Went on-line in October 1998). It is the largest (known) private skins collection in the world, with just over 55,500 skins and themes for 200+ different appliations.
Some of the older skins in years past were only a few hundred kb in size.