How much is a 100 carat pink diamond?

If you found such a stone, you could probably sell it for whatever amount you want.

You can follow the link, below, and find the largest pink diamond currently available for sale commercially.

You may be able to buy a larger pink diamond at an auction. Currently, the largest pink diamond to change hands at an auction is the Graff Pink, weighing 24.78 carats, rated as a Fancy Intense Pink, which sold in 2010 for US$46,000,000. You can learn more about it, below.