Hi, I am reading that one of the possible options, apart from fusion drive and HDD is a 768GB SSD..... I am tempted to have a SSD as big as this as my main disc and then get more space with a USB 3.0 external drive... however... how much do you think that will cost? I am worried that may add $1K to the final price ... do you think it would be on that ballpark? Also, I am surprised of such a large SSD.... I thought that anything above 512 GB faced limitations... maybe they have a couple of drives in Raid 0? any thoughts on this??