No, I really hope you DO sell it for that amount and more. I am a long time advocate of .io domains. Been selling them on Flippa and other Marketplaces for a while now. Also speculated with 3L .io domains, which I decided to stop selling on Flippa due to extremely low market value currently.
I also have 2 .io domains currently on auction at Flippa, and would like to see the .io market expand and get stronger. Well done for selling coinz.io for a good price!