When you are playing God of War, you will soon find a lot of different Artefacts all around Midgard and the other realms. If you collect an entire set, you will get a lot of XP, but you can also choose to sell these Artefacts at any point. But should you sell the Artefacts you find?
The answer is that you should always sell all the Artefacts you find at the first chance. Most of them can be sold for a nice sum of money, and they have absolutely no use to the player after you have picked them up from the ground. So sell them for a decent amount of Hacksilver when you have the chance to, and use that money on something more important than Artefacts.
You can sell your Artefacts before you complete the entire set, since the collection tab will register how many Artefacts you find, not how many you keep. So you do not need to find the entire set before you sell the Artefacts you find.