Gareth Bale has cost Real Madrid £7.2 million during his time out injured over the past 2 seasons.
Dele Alli cost £5m....
Bale's a kick and run merchant with a decent freekick and header, who excelled at Spurs/for Wales as THE focal player; the current team is about the collective, and he'd be exposed for his weak build-up play. Alli and Kane are better technicians and team-players, work harder and in real terms should be regarded as superior players.
I can see Madrid wanting to sell him soon, given the emergence of Asenio and Lucas plus the pending arrival of Hazard. Regardless of the first option attained as part of the sale, it wouldn't be a good move.