This is the CLI-based importer that we custom built to retain all primary keys and import EVERYTHING from vBulletin 4 to XenForo 1.1.3. It will absolutely NOT work out of the box for any site other than ours, and will require programming work on your end to customize it for your site.
That being said, we were able to do a complete import with over 18M posts (75M+ total records) in less than an hour.
The "$25 cost" is actually the maximum cost for 1 month of premium membership on our site. If you are already a premium member, it's free.