I can’t get on board with your 2,150-2,250 or more prediction had he stayed in the NHL though. 1) he may not have been able to hold up had he stuck around in NHL vs playing in Europe and 2) he scored 71pts the year before he left and 54pts the year he came back…those predictions would require him to have been scoring 76-110pts each of those years. So, the low end guess I think would have fairly unlikely and the high end basically impossible
Seems like you're overlooking 1994-95 and 2004-05. By '95, Jagr was one of the league’s top two players in the game and missed out on around 50 points (including 20 goals) due to the lockout. The impact of 2005 is less certain, depending on whether the league would have made the same scoring changes as they did in '06. Either way, he was still performing at a point-per-game level, so conservatively, we're looking at 80 points and in the range of 30-40 goals. But hitting 100 points that season also isn’t entirely unrealistic, as leaving Washington rejuvenated his career.
As for the three years he played in Russia, an additional 200-210 points (with 80-90 goals) is more than reasonable. Though personally I have a hard time believing he would have just been a high 60 high 20 goal guy in everyone of those years, he had years where his scoring popped when he was much older. That said I do agree he would have retired earlier because of that extra mileage, though considering the dude is still playing hockey today I don't think he loses more than 3 years - his longevity is legendary, second only to Howe. That cuts off 44 goals and 119 points from his totals. Taking all that into account and his career totals end in the range of 2,130 and 2,160 points and 850-870 goals.