Put it up on an exchange platform. Personally, I think it is hard to do a trade like this when you are unsure of where the seller is in their own valuation. An exchange allows you to post your own value and see if there are any buyers. You could also setup some tiered pricing. It also allows little buyers to get in on the action. I would love to pick up a few hundred thousand, but I can't come close to buying your full 4 million.