If something is worth 10 million dollars today what would it be worth in 200 years?

There is no answer to your question, it is unpredictable.

For example, the price of gold has gone up to levels unprecedented since the 1980's, but it will probably go back down. Electronics are very expensive when they first come out, but when the technology becomes common, prices drop. Art values depend a lot on whose work is perceived to be important. A famous artist could paint a canvas a solid color and get a lot of money for it. I could do the same thing and my husband would assume I'm trying out the color before repainting the living room.