It was an initial meeting and a lot of headway was made considering an agreement of nuclear disarmament was signed. The US didn't have to give up anything. At least we didn't offer up $150 billion and airlift $1.8billion in cash to Kim and agree not to have US inspector access to nuke sites for verification purposes like the Iran deal.
The amount freed up in the Iran deal was held in various banks globally under the parameters of the sanctions. The total amount has been disputed but estimated as much as $150billion. Yes, Iran got that money when sanctions were lifted. It is argued that it was Iran's money to begin with so they just got it back. It was deposited under the Shah of Iran's rule before he was deposed. Releasing those funds to a violent, terrorist supporting theocracy does not constitute returning those funds to the Iranian public, as seen by the huge increase in proxy war funding in the region since they received those funds.
The $1.8billion in cash came straight from US coffers.
And yes, Trump was just nominated for a Nobel Peace prize. That's not an opinion.