£100M for guaranteed goals, and a player directly responsible for 22 points last season is well worth it.
He converts roughly a bit more than the npxg (quality of chances provided). Given we regularly produce better chances than spurs does, there is no reason to think he would score less goals. His goals converted to npxg is +0.14 - Martial had a npxg of 0.6, Wout 0.5. Kane would normally score 0.6 - 0.7 - 22 - 27 goals. That is 16 - 21 non penalty goals more than we had this season - purely based on the chances created for our current strikers, and not taking into account Kane's superior movement. Now, that is before we even look at his ability to create goalscoring opportunities for others.
15-21 goals equals on average anywhere from 10 to 24 points in the PL (depending on defence). We finished 14 points behind City with clearly inferior number 9s.
Rarely has there been a more obvious player for a side to buy. He instantly makes us contenders.