The Ligue 1 club's total outlay on the Brazilian is expected to be £400m.
Asked if he was motivated by money at his official unveiling at the Parc des Princes, Neymar replied: "What I say to these people is they don't know anything about my personal life, I was never motivated by money.
"If I was following the money, I would be somewhere else, with other clubs in other countries. I'm really sad that people still think that way and I'm glad that PSG believe in me."
Al Khelaifi added: "Neymar came here for motivation, a project that he believed in. He can get much more money than we give him, that's for sure".
Former Portugal winger Figo left Barcelona for rivals Real Madrid in 2000, for a then world-record fee of £37.4m, after Madrid paid his buyout clause. The move was greeted with anger by Barcelona fans.
When asked how he felt about being compared to Figo, Neymar said: "I have done nothing bad. I am sad about the fact that the fans think that.
"You are not obligated to remain at a club, if you wish to leave then the player has that right."
Al Khelaifi added: "He left as a gentleman. It's not fair to compare him with other players. He was trying to delay the process out of respect for Barcelona's players and fans.
"I'm shocked by the question."
'Don't worry about FFP'
Neymar's move was protracted as Liga officials rejected the payment of his buyout clause from his lawyers. They instead had to deposit the money at Barcelona's club office.
The La Liga stance is that French club PSG are violating Uefa's Financial Fair Play (FFP) rules, and Barcelona previously said they would report PSG to European football's governing body Uefa for a FFP breach.
Al Khelaifi defended the deal, saying: "We will be very transparent with Financial Fair Play, I have a strong team with me. If you are thinking about it, go have a coffee and don't worry about it.
"There is only one decision that matters and that is with Uefa. We are working very transparently with Uefa.
"We don't care about speculation in the media. We care that what we are doing is transparent and completely legal."
'Today it is expensive'
Al Khelaifi said Neymar has had an instant financial impact, adding: "Before Neymar the value of the club was $1bn, now it is $1.5bn."
Defending the cost of the transfer, he said: "Today is expensive but in two or three years? I do not think it is expensive, we will definitely make more money. This is the power of PSG. It is an amazing transfer."
Neymar, who denied he left Barcelona to step out of Lionel Messi's shadow, added: "It is not a burden. I am 69kg and do not have a burden on my back."
Paris clamour for Neymar
Neymar arrived in Paris by private jet on Friday and was greeted by PSG officials, including the recently retired former left-back and Brazil international Maxwell.
The club's shop on the Champs-Elysees was adorned with images of Neymar and hundreds of fans queued to get their hands on a replica shirt of their new number 10, which set them back over £100.