One big-money deal took a star turn away from north London and to the Spanish capital in 2013.
Wales international Bale has enjoyed a trophy-laden spell in Madrid, while recording more than 100 goals, but has faced questions of his form and fitness throughout.
Eriksen is now being linked with a similar switch, as he is yet to commit to fresh terms with Spurs, but has been urged to consider his options carefully before making a big call on his future.
Former Tottenham striker Berbatov told the Daily Star: “Eriksen needs to ask himself if he would be happy there. Look at Gareth Bale. He left Spurs for Real Madrid and has won everything.
“But he still gets criticised, even though he scored so many unbelievable goals there, in the Champions League final even!
“He should be a Real Madrid hero. But still, people don’t love him so much. What the f*ck does he need to do?!
“Eriksen will ask himself this question. He will be thinking: ‘Will I be happy there?’ He’s going to be sitting at home thinking about it and his head will spin.
“You are a human being. What happens if you go to Real Madrid? You think: ‘Wow it’s a good move for me.’ But then you think: ‘Am I going to play enough?’
“What happens if you don’t play? At Spurs, the team revolves around him. At Real Madrid there are a lot of big players. Would he fit in there? You start asking all these questions.
“Then you start to lose your focus. So as soon as he can find the answer and resolve it – and it doesn’t matter what the answer is – it will be better for everyone.”
Whatever Eriksen decides to do, Berbatov believes Tottenham will remain on an upwards trajectory as no one player is bigger than the club.
He added: “You don’t want a player who doesn’t want to be in the team, because it’s not good for anyone. I think Spurs is the right place for him. I want him to stay.
“But if his personal view of how he wants his career to go is different, then he will choose to leave. You follow your own path.
“Some players will suffer for their club. But every club will survive. You can replace anyone. Is he good enough for Real Madrid? I don’t know.”
For now, Eriksen is looking to help Spurs wrap up a top-four finish in the Premier League while chasing down a place in the Champions League final.
They currently trail his former club Ajax 1-0 at the semi-final stage of elite European competition, with a trip to Amsterdam for a must-win clash set to be taken in on Wednesday.