Yes, everything Trump does or doesn't do is about money. But back in the 80s, if--as has long been reported--Trump was turned by the then Soviet Union--Putin wasn't running the show. At the time, he was just a relatively lowly KGB officer. Donnie would have been in his early 40s. Putin would have been almost 10 years younger.
So if Trump established a relationship with the Soviets at that time, I doubt Putin played a role in it immediately. But Trump has never been able to keep anything secret. So my guess is that nothing really happened at that time. Then the USSR broke up in December 1991, and everything changed.
Putin had no objection to the totalitarian empire he'd grown up in, and when it lost many of its satellite republics--Ukraine was one of the largest and most valuable--Putin was upset. Flash forward 35 years: Vlad wants to reconstitute the Soviet empire.
Trump doesn't understand any of that. He's not a history buff, to say the very least. So Pooty may have sold him some other story to win his loyalty. Returning to the first line of this post, for Trumpty, everything is about money.