I haven't really looked at BoE epics in Cataclysm so far as I've always been quite short of gold. However, today I looted Je'Tze's Sparkling Tiara (http://www.wowhead.com/item=67147/je...parkling-tiara) and decided to try to sell it. When trying to decide a price, I noticed most of the BoE cloth gear with spirit is on the AH for 30-40k gold! Seriously, does anyone really buy gear this expensive? O_o
world drops are more expensive obviously, especially if there's not a rep epic in that slot, so people are willing to pay it because it's probably gonna last them til heroic raids. crafted cloth stuff however is down below 4k usually, on my realm.
They seem to sell for that much yeah. There is a decent chunk of players who have stockpiled so much gold since TBC/wotlk that even though the gold intake from wotlk > cata wasn't increased by that much the price of items that aren't mass produced have increased 5-6fold or more.
I paid about 120k for every single epic boe available for my priest at the beginning of cata. Considering it was right at the beginning of the expansion I ended up with some good deals as no-one knew how much they should charge for anything - I got that helm for 9k and the person selling it thought I was being generous offering him that! On my server now it goes for about 20k.
The other thing to keep in mind is that prices fluctuate all the time for these items as typically people don't see anything in the AH and decide the going rate for themselves.