not that they were guaranteed micron-e die causing the prices to hike. it is because A) the product line has long been discounted. B) the specific line of ram is known to overclock well and popular at the time because it was budget and offer performances like no other.
this is not so true anymore. Samsung B die is still expensive but not as expensive as 1 year ago now. the new Micron E die dont overclock as well but can do tighter timings at the rated speed. the new Hynix stuff are immense in terms of raw clock speed and seems to offer the best compatibility with motherboard and CPU across the range.