He's worth what Levy says he's worth and what City are willing to pay. If the two don't converge by enough, then he doesn't move.
Is Kane worth only double Ben White? Just over double a Varane with 1 year left on his contract? Less than Lukaku? The same as Graelish? And more particularly, is he worth those amounts to the club selling him, when we'll have to replace his impact on the team?
I personally have no interest in a Saville row suit costing thousands of pounds but have some colleagues who think I'm essentially a simpleton for not owning one. Similarly, they think I'm crazy for the amount of money I spend on football tickets, even though I only go 5-6 times a season now. For me, £80 for a Spurs ticket is worth it. For others, its a ludicrous amount of money. Worth and value are not always objective measures.
If Kane is still here come the end of the transfer window, he'll sharpen up. He cares too much about personal records (like beating Shearer) and the world cup (just a season away) to sit and sulk all season.