"Yeah, it's a lot of money," Peters told reporters Friday after practice, via ESPN's Lindsey Thiry. "But it was worth it."
Peters made the gesture while returning a Derek Carr interception for a touchdown late in the fourth quarter, sealing the victory for Los Angeles.
The celebration was a tribute to Raiders running back Marshawn Lynch - a close friend of Peters - who once famously grabbed his crotch while soaring into the end zone as a member of the Seattle Seahawks. Both Peters and Lynch hail from Oakland.
"It's all paying respect and loving the game," Peters said.
"Who knows if this (is) Marshawn's last year playing in the league," he added. "S---, we was up, closed the game out, no better way to go out in Oakland. Who knows the next time we'll get to play the Raiders in Oakland - they're going to Vegas in what, a year and a half? So it was something that was well-deserved for the hometown."
Rams head coach Sean McVay also shrugged off the punishment handed to Peters by the NFL.
"He's got a close relationship with Marshawn," McVay said. "This was something that he had discussed with him before, if he was going to be able to make a play like that. So it was a good way for those guys to kind of have an inside joke, laugh about it, and I think it all was in fun and lighthearted."
Peters had three tackles and the interception in his Rams debut. He was acquired from the Kansas City Chiefs in a blockbuster trade in March.