If the person who finds the artifact puts it in the museum, that person will become famous! People from everywhere will come and see the artifact (depending on how important the artifact is), whereas if you put the treasure on an auction, only a couple hundred people would know about the person. The person's face will be on newspaper articles (also depending on how important the treasure is) if he/she put it in the museum.

The treasure hunters also put the artifacts on auction. You might be wondering, why doesn't the museum buy it from the seller? Well, the museum doesn't make a lot of money, and it's only income of money is by admission fees. The museums also have to pay a lot of money for the maintainence of the museum. It would be kind of the treasure finder to donate the treasure he found to the museum. T. Rex bones are being sold for the second time in the history of the world! If the bones are sold to people, the rest of the world can't see them!

The location of the treasure matters too. If the location the treasure is found is, let's say, the Red Sea, It wouldn't be right to sell it to someone in Japan! It would be more considerate to put it in the museum that is around the Red Sea because the artifact could mean a lot to the people who live near the Red Sea.

Scientist learn more about our past and ancient history by historical artifacts. If the historical artifacts were in a house, scientist might never be able to learn about them, because it wouldn't be polite to go ring a doorbell and say,

"Hi! I am a scientist! I heard that you had a historical artifact. Can I come in to see it?"

They would definitely close the door on you, whereas if the same artifact was in a museum, the scientist could simply pay admission to see the same artifact and not get embarrassed. That scientist would easily get the job done and tell the world of his discoveries.

When the treasure finders auction the treasure, it gives ideas to the buyers. The buyers may think, 'That treasure finder is going to make a lot of money with that artifact. Maybe, if I go treasure hunting, I will find a treasure and make tons of money!'.

This will turn into a big problem. People who are not trained to search for artifacts could damage the artifact while trying to find it, and worse, they could hurt themselves in the process! Scientist will be much better at this, because they are trained, and prepare for the worst and hope for the best.

This concludes my talk. Artifacts are very helpful to learn about, and that can only happen if the world can see it. Where else would be a proper place to put the treasure besides the museum? In a museum, it is always kept safe, no matter what.