Igor, I have two EX II's, a 240GB and 480GB.
They have been very cheap in the USA, the 240GB for $160, and the 480GB is easily found at $300. I just checked a major online retailer in the USA, and they have the 480GB EX II for $260 today.
I don't know why they are so cheap (for SSDs of course), Samsung is a very strong competitor, great reputation and products, and they keep the prices down, at least on the EVO, so SanDisk may be fighting them for business. Most people buy the EVO instead of the EX II for almost the same price and capacity. I could have bought another EVO for the same price and similar capacity as the Extreme II, but I prefer the EX II.
I have the 840 Pro, 840 EVO, and SanDisk EX II, and IMO they are all among the top SATA III SSDs we can get. They all boot an OS at the same speed in my experience, but each has their own plus and minus in some aspects of performance compared to each other.
Those differences are in the extreme circumstances that most of us rarely if ever have in our PC usage. The PC hardware reviewers have had to go to great lengths to find differences between these SSDs, and many of those differences won't be needed or noticed by the majority of us.
OTOH, I do notice the differences between SSDs occasionally, others I have used boot an OS slower than these three. The differences are five seconds at most, mostly less. Imagine you're dragging and dropping a ~20MB - 100MB file or folder from one SSD to another (if you have such a system), and think of the Windows dialog box that appears that shows the rate/speed of the file copy. I don't see that display anymore (unless I'm using a USB flash drive), the copy is done before it can appear.
Yes Igor, a 1TB EX II would be a nice SSD!