Clubs in the Saudi Professional League have invested heavily in attracting big names such as Cristiano Ronaldo, Karim Benzema and Neymar in recent years.
In December, FIFA confirmed that Saudi Arabia would host the 2034 Men's World Cup, a decision that Harris criticized.
Solihull-born Young joined Saints in September 2023 after leaving Aston Villa, and went on to score 22 goals for the Welsh champions, winning the Cymru Premier Player of the Season award.
Young scored twice on his European debut as part of a run that saw Craig Harrison's side eventually secure a historic place in the group stage of the European Conference League.
But the 21-year-old left Saints ahead of the club's Conference League campaign, much to Harris' frustration.
Harris added: “They came on the last day before the transfer window closed and upset our player, and they promised the world.”
“We are not a selling club, we did not want to sell him. The money they were offering him changed his life.”
“This guy from Saudi Arabia was saying ‘We are this, we are that’ and that they have a lot of douches. I didn’t want that – I wanted the player to play in Europe.”
“We missed the deadline and played in Europe without a striker. We couldn't bring in another player. We represented Wales in Europe and the difference was that we didn't score enough goals.
“If we had a player of his caliber I would say we would have had a better chance.”