50 levels above your current level is probably too high. But consider 35 levels higher or even more in a team. You also have to take into account that you can kill stronger mobs that have a higher experience multiplier but still are in a level range you can hit without missing too much. The current system limits you to 6k even though it would probably feel more rewarding to get the full experience you could earn, killing Kinchers 20 levels above your level.
