Whew, upgrading your current Steam copy of Dark Souls II just became way more appetizing (if a little complicated). If you intend to get the DX11 version of the game (which features retooled enemy placement and item locations) but already own DS2 on PC, then it will cost $30 instead of $50. If you’ve bought the three Crown expansions as well, then it will be $20. If you already own Dark Souls II and the Lost Crowns DLC but don’t want to (or don’t have a rig that allows) upgrade to the DX11 version, there will be no incentive to spend the money on the DX9 version of Scholar of the First Sin. It will be priced cheaper than the DX11 client, but won’t feature any of the next-gen enhancements. This is the same case on PS3/360; those versions of Scholar of the First are basically the GOTY Edition compiled with the Crown season pass and the free Scholar update patch, but otherwise have no new added content.
Also, save files from PS3/360 cannot be carried to XB1/PS4, and save files from the current DS2 client on PC cannot be transferred to the DX11 Scholar of the First Sin client.