Extremely generous of you! I'm currently attempting to roll back the install to version 3.8x and get a refund (seems prudent)...I'll see how that goes...I may, then, just be able to go from that to Xenforo.
Let me ask another related silly question...has anyone dealt with the resulting 404 tsunami from upgrading an older VBSEO-enabled site to vB 5? I'm hoping there is an .htaccess fix that doesn't involve 10,000 individual redirects...