I think it's pretty clear cut why some players choose Spurs over signing for that mega rich club with higher wages. Game time, Eriksen walked into their starting 11 and has grown his game playing week in and week out. He opted for Spurs over City who were in for him as well simply because he would of been sat on the bench behind Silva. Could he have dislodged Silva? Arguable, he certainly didnt have that issue at Spurs. He could still look for that big money move later in his career and would demand a decent wage with the skills he now has.
We see that again with Sanchez, Barca, Bayern, Juve, a host of big clubs were in for him, but he chose a lower wage for what he perceives as more game time, walked into the starting 11 for Spurs. Seems like Sanchez hasnt missed a game except the suspension since he joined.
Spurs are a great stepping stone club for talented young players. Great facilities, top coach, well situated in London, I can see why they are attractive to young talent that is hungry for game time. Players can easily spend their early years at Spurs, then if they so wish, look for a large wage move later on in their career eg Bale. If they are good enough, big clubs will want them, and pay them accordingly.