"Best and final" arrives on a schedule, usually near the vendor's quarter-end. It is a tactic, not a fact. The renewal can almost always move — the question is whether you have given yourself the room to move it.
Room comes from time and alternatives. If you start early enough to make a switch credible, the ceiling rises. If you wait until the licenses lapse, it does not.
Test the number with specifics: a benchmark, a re-scoped metric, a multi-year structure that helps the vendor's forecast in exchange for a better unit price. Each gives them a way to say yes without losing face.
Done with discipline, reopening a 'final' renewal returns real money and leaves the relationship intact. That combination is the point.