I think what you are describing is correct. It is a blind auction. You can speculate on the price based on the transactions so far but really anything could happen. For the longest time I did not intend to participate given that I really don't like ETH and was happy to be patient. However, the market is so irrational, I decided to contribute at least something to this window. What happens after that is anybody's guess. If anyone says they know, they are either liars, stupid or out to manipulate you :)