https://wccftech.com/red-dead-redemption-2-initial-uk-sales/

Red Dead Redemption 2 launched last Friday to unanimous critical acclaim, including ours. The strong review scores drove the analysts at Piper Jaffray to raise their sales estimates for the game to 18-20 million units by March 2019, from their previous estimate of 15.5 million units.

With regards to first weekend sales, they surmised Red Dead Redemption 2 could sell six to eight million units for a total of 400 to 500 million dollars in revenue.