I'm not trying to talk you out of it, but note that Sensaphonics makes custom silicon sleeves for Shure universal IEMs. I have a pair for my SE530s. Note they don't have a version for the E2c, but I've noticed that due to the flexible nature of the material, and the somewhat generic shaped hole, the sleeves will accommodate a fairly wide range of IEMs if you aren't too picky where the cable comes out (upside down, that kind of thing).
Keep in mind there are a lot of little costs that add up with UM (not their fault). I decided to re-shell my SE530s due to ongoing cable issues. Here is my cost breakdown so far:
- Impressions $40
- Shipping to China $78 ("Express" via FedEx. There are probably less expensive options. This method will take aprox. 5 days).
- Re-shell $159 (return shipping included)
- Cable (yes, no cabled included), $42.73 after shipping for Westone ES cable.
So looks like your cost would be about that minus $40 unless you already have cables.
Here are some pics of my sleeves:
Fisher Hearing is cheaper doing re-shells, but it sounds like (looking at the comments, above) they may not do the E2c.
Also note if you are a bit adventurous you might be able to make some custom sleeves yourself on the cheap:
Rewiring an ER-6i just aint that hard, folks. Pics enclosed.
Possible material for DIY custom sleeves