I like the idea of it but there's a few problems with it
If a bunch of people grab it for free, then Baddy deactivates the IDs when it's over, we could be skipping 1,000 or more IDs.
If that isn't how it works, consider the following situation:
Blockhead200002 joins Pecon7's server and gets banned forever. A few years later, when this ID is actually sold, a completely different person tries to join Pecon7's under this key, but can't because said ID was banned in the past.
The only workaround I can find is to have letters in the IDs ( ex S1018 ) or absurdly high IDs we'll probably never reach ( such as 7806900 )