How long to beat the main questline of Assassin’s Creed Origins on hard difficulty? Took me around 35-40 hours.
When you get to 40, similarly to Destiny, you can continue to level, and each time you relevel, you get another experience point.
►Do not go out of your way to do the strongholds and bases, many sidequests will have an objective right in an enemy base
►DO NOT waste skill points on XP boosters! The XP boost you get is minimal, like 10 xp, compared to completing a sidequest, which is usually a few thousand XP
►SAVE YOUR MONEY for late game upgrades! It is very expensive to upgrade your legendary weapons. When you upgrade a weapon, it goes up to your current level, and the price of upgrading does not change regardless of how many levels the weapon goes up
►Upgrading a level 1 weapon to 40 costs the same as 35 to 40
Also, I am not sure if this was due to a glitch, or part of the story that I missed, but a few times throughout the game, I lost every piece of gold I had. So I would recommend NOT selling your junk until you have completed the story