yes this instabuy is just a way to sell the premine. nothing more.
It's funds from ICO and bounty which was left there and don't be withdrawn for more than one year. Premine is untouched. And all funds will be returned back to that wallet by the time.
What do you mean pre-mine is untouched?!
XWkxDTkp9uzvtMCE7NRVphzbwMigLrzyzK - This is instabuys cold wallet address and surprise surprise this is also where the pre-mine landed. They are literally selling pre-mine. You can see it on the chain.