because it is so hard to get your hands on a large amount of bitcoins - that they could be sold for a higher price if sold as a large sum
The opposite is also true. It's hard to sell large amount of bitcoins. In both cases it's actually not hard, you just send an order and it takes seconds
but it is hard if you don't want to move the price. You are assuming that there is a lot of buying interest for bitcoins. If that's true, the very nature of the open market solves the problem by moving the price higher. No need to create blocks of bitcoins available to purchase at a higher price. if you see the market depth of any exchange you have that already. In fact, the availability of a large quantity of bitcoins for sale would be a reason for a price drop, and typically if you do have such quantity available you would negotiate a sale at below market price, not above. Big blocks of shares trade like that.