All of this had been within Deathstroke's expectations, and evidently within Luthor's as well.
There was no way Grodd would have spoken like that without Luthor's instructions. The great ape was not the talkative type; he always did more than he said, making him the most dependable member of the Legion of Doom.
Su Ming had also noticed that all the souvenirs they had bought in the village earlier had vanished, leaving only the green Doll Sinestro had kept.
A little deduction made it clear.
The village they were currently in lay within a special dimension formed by a Timeline. Luthor wanted to collect things from here to study the effects of spacetime magic on matter, especially objects made by the people living here.
Darkseid wanting to kidnap The Flash meant he was also eyeing spacetime. Luthor was probably trying to cram at the last minute, at least learn enough to fake being an expert.
But he had not brought any gold. As a wealthy tycoon, he could not possibly lower himself to ask Deathstroke for money, so he silently communicated with the Legion of Doom members through the great ape's Psionic Power, having them take money from Deathstroke and purchase experimental materials for him.
Those purchased items were probably stored in the carrying compartments of Luthor's armor, and he would never mention the matter openly.
As for upgrading Cyborg, Luthor had no reason to oppose Deathstroke. Deliberately steering the conversation in the opposite direction was meant to create an illusion for Victor.
To make him think that upgrading was a good thing, but that the Legion of Doom did not want to help him, and only Deathstroke and Damian truly had his best interests at heart.
This was the classic good-cop-bad-cop routine. Luthor and Deathstroke had a silent understanding;