Both the Pacers and Thunder are non-taxpayers. This is the first time the NBA Finals has featured a matchup where neither team paid the luxury tax to get there.
The NBA instituted the luxury tax system for the 2001-02 season. However, that first season and the 2005-05 season did not meet sufficient BRI requirements to trigger the luxury tax.
In each of the other 21 NBA Finals, either the winning or losing team was a taxpayer in that season. Of those 21 NBA Finals, 16 of the winning teams were taxpayers. Somewhat surprisingly, only five NBA Finals featured matchups where both teams were taxpayers.