The Brazil star finalised his move from Barcelona on Thursday after PSG paid his $A331 million release clause in full, smashing the world transfer record in the process.
Combined with a reported annual salary of $A44m after tax over five years and various bonus payments, the full cost of the deal to bring Neymar to the French capital could reach a staggering $A550m.
The sums involved have led to widespread concern that PSG will be unable to comply with UEFA's FFP regulations, which are intended to prevent clubs from spending beyond their means and encountering financial difficulty.
LaLiga initially refused to accept payment of Neymar's release clause after reportedly expressing concern at being complicit in a deal that breaches FFP rules, while FIFPro has called on the European Commission to investigate.
UEFA said it would look into the deal to ensure the rules were being followed but Al-Khelaifi is adamant that there is no need for PSG fans to worry.
"Maybe today it's the most expensive transfer [of all time], but in two or three years..." he said at Neymar's official presentation.
"I don't think it's too expensive because I'm sure we'll make more money than we've paid. The Neymar brand with the Paris Saint-Germain brand. It's an amazing transfer for everybody.
"We've been very transparent from day one and we will be until our last day. There's no problem with Financial Fair Play. We're within the regulations.
"Whoever's thinking about Financial Fair Play, please, go have a coffee, we're fine."
Al-Khelaifi claims Neymar's arrival has already boosted the value of PSG by half a billion dollars, with the transfer the biggest step yet taken by the club in their quest to win the Champions League for the first time.
"For sure, everybody knows our aim is to win the Champions League," he said. "As I said at the beginning, we want to win as many trophies as we can. It's our target but we can't say 'this year, we're going to win it'.
"Before Neymar, the value of the club was $1billion. Now, it's $1.5bn. I'd love to meet you in two years and say what the value of Neymar will be. Double, at least."