Neat John Byrne covers, eh?
Beyonder turns an office building into gold to pay for a new suit of clothes, but in so doing the structure collapses and people are trapped. Spidey crawls through the wreckage to save them.
Then the US Government asks Kingpin to protect all that gold while they figure out what to do with it. So of course Kingpin tries to steal it.
Very odd plot device. it makes no sense at all that in a world with two Avengers teams, the Defenders, and dozens of costumed do-gooders, the government would ask the kingpin to protect the gold.