Today when a user wants increase in mailbox, management likes us to provide the user a mailbox report of all their folders, so maybe they can see some folders that they can clean up. I know this can be easily found in Outlook by the user, but management will be management.  So run the report, we normally use "get-mailboxstatistics | select name, foldersize" and export it to CSV.

This has two downsides

1) depending on size of folder, it will show in kb, or mb, which is not easily sortable in excel. I'd prefer it to be all in MB, but I forget how to do this.

2) This report includes folders like "Purges", "Versions", "Recoverable Items" "Deletions" which I do not believe count towards mailbox quota. Also, these are not folders the user can access.

Does anyone know how I can edit the command I run to resolve these two issues?

looks like exactly what you are looking for

http://exchangeserverpro.com/reporting-mailbox-folder-sizes-with-powershell/