Average file size statistics
You can do this pretty easily in Powershell
$items = Get-ChildItem -path "c:\your\file\path" -recurse
$count = ($items | measure-object | select -expand Count)
$size = (($items | Measure-Object -property length -sum).sum /1MB)
$avrg = $size / $count
$avrg
Output example:
PS X:\> $avrg
1.03643417358398
Someone over at Seven Forums pointed me out to Agent Ransack from Mythicsoft:
http://www.mythicsoft.com/page.aspx?type=agentransack&page=home
Had to make the calculations on my own but it wasn't so bad.