With the Shure line, maybe look for a pair of well-treated older models second-hand. If I understand the Shure product line correctly, their 'new products' are essentially identical to the old ones just in different casings and the lineup shuffled around at bit with an extra mid-range model (which means that a like-new pair from the old range will be just as good).
Check out the used listings on
www.head-fi.org. You can probably pick up some Shure e4c's for a good price (which are what I've got) and buy a new set of tips for the end which means the actual bit in contact with your ear is brand new.