I am very interested to know what other mechanisms exist to purchase bitcoins, the only ones I know of are:
- Exchanges
- Coinbase
- BTC ATMs
- In-person cash sales
In person cash sales & ATMs are not going to provide the $millions in volume needed and coinbase has daily limits and uses exchanges in the back end anyway.
So... Where else can BIT purchase?
Find one or more large holders, make contracts with them. Something along the lines of agreeing to buy X BTC for Y USD each over Z months, for example. Now you've locked in a price and your liabilities are better known than if you were just going to buy on the exchanges as needed. Chances are, you'll get a pretty decent rate when buying in bulk, too.