I have just made an worgen druid alt and sent him some heirlooms. To my surprise as i picked them up from mail i saw that they have them blue letters saying i have 2hrs to sell em back for refund.
Now i imagine it wouldnt be too hard to get to Stormwind in them 2 hours then get a dalaran portal and switch them for some other heirlooms.
Basicly this way you only need to ever buy one set of heirlooms and simply change them whenever you decide to roll an alt which needs different type of heriloom.
I didnt try selling them yet since im still at sub 10 lvl worgen zone but i wonder has anyone done this?
---------- Post added 2011-01-04 at 02:59 PM ----------
By the way these herilooms are not new, i bought them waaaay back and already lvled 2 different alts with them