It depends how you perceive your opponent will perform.
When I was in div IV, my playoff final was against an relatively inactive team. I beat him by 20 in the first game at home. I knew I could smash him again so I tanked the second game, played TIE and then went to beat him again in game 3. Extra match income.
In div III, my playoff final was against an active team. I just squeezed in a victory away in game 1. Having just won away from home, I had no intention of taking it to game 3 if I could help it as winning away from home is not an easy task so I played to win game 2.