I can afford to buy one bis piece. I mostly play unholy dps. I'd like something that is hard to get. I was thinking maybe HC bryntrolll, although I'm not sure if that is bis.
I'd replace your Needle-Encrusted Scorpion. It's a rather garbage trinket in general and even more so for unholy. Your options are pmuch DBW/STS (with DV/DC heroic being 3rd bis). Out of the two I'd get STS as it is rather hard to get compared to DBW normal/heroic.
P.S. You should fix your hit rating while you're at it.
Noone needs Bryntroll HC. The moment it drops from Marrow HC u will get it 99%.
Sharpened Twilight Scale (or DV HC if u think u will get it easier than STS), or Glorenzelg if u want to play Unholy, or Havoc's if u want to play Frost.
I mostly play unholy (even though frost is higher dose in most fights), I'm going to see in rawr what gives most dps, although I'll probably just hey sts because I really need to upgrade my trinkets... Why does noon need bryntroll HC? I thought it procs a lot with dk(due to abilities?)
It's easy in the sense that killing the boss that drops it is done on a regular basis by basically every pug, maybe not on heroic, but at least on normal. Compared to that a lot less pugs kill RS normal and none kill heroic (as far as I'm aware anyway).