Gamora comes up when it looks like they're about to dock. And, once they're settled: "Are you planning to go alone with Rocket and Chewie to do the trade?" she asks. 

"Why, you want to come along and see who you're going to be robbing?"

"Getting a lay of the place will be useful."

"As long as you're not going to fuck things up, I guess."

"Not while you're standing there; and I don't intend to let Tivan know who's robbing him later."

"Fine, then."

All six of them, then? 

Seems like it.

Onwards, then. 

Time to go get fucking paid.

Unfortunately, first they're going to have to wait to be called in to Tivan's office - he doesn't see just anyone who comes in, especially not right away. (Knowhere has plenty of entertainment while they cool their heels, though.)

Might as well get a drink.

There's a pretty wide spread of options. Is she in the mood for rowdy or quiet?

Let's get loud.

Then she can definitely have loud - loud enough even Tivan's servant girl will have to raise her voice when she comes to fetch the visitors. (She's creepily poised, hands together in front of her, posture ramrod straight, voice light and high and flat.)

Weird, but some people are like that. Probably some sort of fuckery Tivan expects from his servants; typically of that kind of rich bastard.

The room the servant leads their group into is enormous, a broad space under a translucent glass dome, though they can't see the far walls - it's full of cages and display cases containing plants and animals and objects and a few scattered humanoids. Most of them Ash has zero familiarity with, but some - some are definitely sapient, just members of exceptionally rare peoples. 

One of them is from the same species as the girl leading them, and looks pretty similar - another girl of a similar height and build with facial features that'd make Ash suspect they were sisters if they were human. The caged girl looks deeply miserable. 

"We house the galaxy's largest collection of relics, flora, and fauna of all manner," the girl leading them says in that same creepy tone. She comes to a dais near the entrance, then turns and bows grandly. "I present to you Taneleer Tivan, the Collector." There's a man with white hair on the dais, past a raised table, who turns towards the as she announces him. 

"Collector." Ash reaches into her pouch to pull out the silvery orb. "I heard you were in the market for this."

"Marvelous," he says, removing his spectacles. "Come here, let me see it more closely, my lovely friend."

What a fucking creep. Rich creep, though, so she does get closer.

He gestures for her to place the orb in an instrument on the table. "Let's see what we have..."

"Something worth a hell of a lot of money."

"More than than..." he murmurs as the instrument hums to life, holding the orb suspended - and slowly unscrewing it, pulling the two halves apart to reveal something brilliantly glowing within. "This... This is unique. One of a set of only six, out of anywhere in the universe."

Damn, that thing is pretty shiny.

"In the beginning," he says, rather dramatically, "Even before the beginning of the universe - there were six singularities. And when the universe exploded into being, the Celestials forged their dying hearts into six gems. Six stones, each holding a barely contained infinity in them. Their power is beyond imagining..." He gestures, and holographic displays float into being, some of the brilliant purple light from the gem enveloping and swaddling them. They show a purple light enveloping a planet in catastrophe, a group of powerful men with cracks spreading across their skin as they try in vain to hold its power, a weapon in the hand of a collosus wielded to slaughter even greater enemies... More, a hundred miniature snapshots of times the Power Stone has been activated, always to devastating effect.

It's notably all information that neither 9S nor Gamora could find on the Infinity Stones. 

Tivan shivers in delight. "Isn't it marvelous? Isn't it beyond compare?"