It strikes me that it is actually a really good time to sell him. You'll need to bear with me on this but the reasons I see are:
1. His ankles.
2. His contracted value to the club
3. Our over reliance on him
4. The scope £150m would give a manager to shape a new Tottenham.
1 - the ankles - he's now missed what - 30 games in 3 seasons due to ankle injuries? A couple more as he gets closer to the magic 3-0 and he will be missing half a season after a knock - or worse get a serious ligament issue and spend 12 months on the side lines.
2. - his value - he's just had the best season of any previously - his game is more complete, his finishing lethal - that makes him THE hottest property in Europe right now, on a par only with Haaland who is a phenomenon. Today we could ask and get £150m+ from one of the oil clubs. Next year it will be lower, and the year after its final year of contract time.
3. We are absurdly, stupidly dependant on him. Each time he gets injured we all collectively sh*t ourselves and hide behind the sofa. There's not many clubs that are that reliant on one player - Liverpool and Van Dyk is about the only example I can think of right now - Wolves/Jiminez and Saints/Ings I guess are close too. We need a strong squad, not a team built around one guy.
4. -cash for a manager - If we bring in a manager whose job, like Rodgers has done at the Foxes, is to get all parts of the team performing better, and not building a team around one player, then we're not badly placed. We have a superb academy and plenty of depth up top in forward positions. We lack an out and out No9 if Kane goes, but would have the funds to secure one. Both Ings and Jiminez actually would work well following that philosophy.