Real Madrid are reported to have proposed a €115m bid for Tottenham's Gareth Bale, which prompted Barca president Sandro Rosell to claim that he values Messi at €580 million - even then, it's unlikely that they will sell the Argentina star.
Alba believes that it would be hard to place a price on Messi, who has won the past four editions of the Ballon d'Or.
"We're talking about the best player in the world. For us, he doesn't have a price. He is No.1. No player can stand up to him, and he'll continue being No.1 for as long as he wants," he told Marca.
When asked about Bale, Alba admitted that he hasn't seen much of the mercurial Welsh winger.
"If I'm honest, I haven't seen him play alot but I know he is a good footballer," Alba continued.
"In each case it depends on the needs of each team, what the club is willing to pay and what the other demands. Then time will tell if a player has been cheap or expensive."
Alba also praised new coach Gerardo Martino for the way he has taken to the role in the Barca dugout, admitting he is happy to work under those who shun the limelight.
"Barcelona has always had calm coaches," he continued.
"We are happy with Tata Martino, as with Tito Vilanova. He is a quiet coach who only wants to talk about football and what happens on the pitch."
"I don't think we're going to change our style nor our way of playing very much. The truth is I like how we play."