Then look up the XP for a certain lvl. For 200, it's 302,200. Then you multiply by 0.2 for the extra XP the battle pass gives you (actually a little bit short of 0.2, cause you only get extra 10% in the beginning and 15% and 20%, respectively, later on). In our example, that would be roughly 60,000. Dividing by 1,500 gives you 40 lvls. 40 times 50 gold are 2000 gold. So if you reach lvl 200 without battle pass, you can expect a little bit less than 2000 extra gold with battle pass.