A gun-toting robber took $600 and an ounce of marijuana from four Pace University students during an early-morning stickup in lower Manhattan, officials said yesterday.

In an odd twist, police sources said one of the students — all in their late teens or early 20s — is a dealer who supplied narcotics to Pace student Max Moreno, who was gunned down in a drug-related attack this fall.

But the dealer in Monday’s robbery is being treated as a victim and is unlikely to be prosecuted for any drugs he might have lost in this stickup, the sources said.

The robbery took place outside 33 Gold St., just down the street from 2 Gold St. where Moreno, 21, was shot in the head in his luxury apartment on Sept. 29.

Moreno had just sold pot to a couple when two attackers burst into the unit, killed him and took off with a mysterious locked box, police said at the time.