Brighton manager Chris Hughton revealed that the Iran forward has long been scouted by the Seagulls and his club-record signing shows how far the Seagulls have come.
"[Jahanbakhsh]'s an exciting prospect for us," Hughton said of the Eredivisie's top scorer in 2017/18, with 21 goals for Alkmaar. "He's a player we knew very well. He nearly signed for us three years ago, so we've followed him well.
"We know the market but we have broken our transfer record some seven times in the last two summers. That's the way the Premier League and the prices are going, and that's the way we're going.
"The starting position always remains the same. I have a responsibility to keep us in the division and to build as a team. But there are challenges. What you want to be able to do is to improve as a team and as a squad, and you ultimately want to improve the position."
Brighton open their 2018/19 Premier League at Watford on Saturday.